RE: [PATCH v6 2/3] dmaeninge: xilinx_dma: Fix bug in multiple frame stores scenario in vdma

[Appana Durga Kedareswara Rao]

Hi Mike Looijmans,

Thanks for the review...
Sorry for the long delay in the reply...
Please find comments inline... 


>On 14-01-17 06:35, Kedareswara rao Appana wrote:
>>  When VDMA is configured for more than one frame in the h/w.
>>  For example h/w is configured for n number of frames, user
>>  Submits n number of frames and triggered the DMA using issue_pending API.
>>
>>  In the current driver flow we are submitting one frame at a time,
>>  But we should submit all the n number of frames at one time
>>  As the h/w is configured for n number of frames.
>
>The hardware can always handle a single frame submission, by using the "park"
>bit. This would make a good "cyclic" implementation too (using vdma as
>framebuffer).
>
>It could also handle all cases for "k" frames where n%k==0 (n is a multiple of
>k) by simply replicating the frame pointers.

Agree with your comments will fix it in the next version.
Somehow didn't get enough time to send next version of the patch series.
Will modify the driver as per your comments and will post next version of the 
patch series at the earliest... 

Regards,
Kedar.

RE: [PATCH v6 2/3] dmaeninge: xilinx_dma: Fix bug in multiple frame stores scenario in vdma

[Appana Durga Kedareswara Rao]

Hi Mike Looijmans,

Thanks for the review...
Sorry for the long delay in the reply...
Please find comments inline... 


>On 14-01-17 06:35, Kedareswara rao Appana wrote:
>>  When VDMA is configured for more than one frame in the h/w.
>>  For example h/w is configured for n number of frames, user
>>  Submits n number of frames and triggered the DMA using issue_pending API.
>>
>>  In the current driver flow we are submitting one frame at a time,
>>  But we should submit all the n number of frames at one time
>>  As the h/w is configured for n number of frames.
>
>The hardware can always handle a single frame submission, by using the "park"
>bit. This would make a good "cyclic" implementation too (using vdma as
>framebuffer).
>
>It could also handle all cases for "k" frames where n%k==0 (n is a multiple of
>k) by simply replicating the frame pointers.

Agree with your comments will fix it in the next version.
Somehow didn't get enough time to send next version of the patch series.
Will modify the driver as per your comments and will post next version of the 
patch series at the earliest... 

Regards,
Kedar.

Re: [PATCH v6 2/3] dmaeninge: xilinx_dma: Fix bug in multiple frame stores scenario in vdma

[Vinod Koul]

On Sat, Jan 14, 2017 at 11:05:54AM +0530, Kedareswara rao Appana wrote:
> When VDMA is configured for more than one frame in the h/w.
> For example h/w is configured for n number of frames, user
> Submits n number of frames and triggered the DMA using issue_pending API.
> 
> In the current driver flow we are submitting one frame at a time,
> But we should submit all the n number of frames at one time
> As the h/w is configured for n number of frames.

Is there a specific reason why you continue to start lines with Title cases, I
have already told you to not do that last time!

> 
> This patch fixes this issue.
> 
> Acked-by: Rob Herring 
> Reviewed-by: Jose Abreu 
> Signed-off-by: Kedareswara rao Appana 
> ---
> Changes for v6:
> ---> Added Rob Acked-by
> ---> Updated commit message as suggested by Vinod.
> Changes for v5:
> ---> Updated xlnx,fstore-config property to xlnx,fstore-enable
>  and updated description as suggested by Rob.
> Changes for v4:
> ---> Add Check for framestore configuration on Transmit case as well
>  as suggested by Jose Abreu.
> ---> Modified the dev_dbg checks to dev_warn checks as suggested
>  by Jose Abreu.
> Changes for v3:
> ---> Added Checks for frame store configuration. If frame store
>  Configuration is not present at the h/w level and user
>  Submits less frames added debug prints in the driver as relevant.
> Changes for v2:
> ---> Fixed race conditions in the driver as suggested by Jose Abreu
> ---> Fixed unnecessray if else checks in the vdma_start_transfer
>  as suggested by Laurent Pinchart.
> 
>  .../devicetree/bindings/dma/xilinx/xilinx_dma.txt  |  2 +
>  drivers/dma/xilinx/xilinx_dma.c| 78 
> +++---
>  2 files changed, 57 insertions(+), 23 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt 
> b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
> index a2b8bfa..e951c09 100644
> --- a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
> +++ b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
> @@ -66,6 +66,8 @@ Optional child node properties:
>  Optional child node properties for VDMA:
>  - xlnx,genlock-mode: Tells Genlock synchronization is
>   enabled/disabled in hardware.
> +- xlnx,fstore-enable: boolean; if defined, it indicates that controller
> + supports frame store configuration.
>  Optional child node properties for AXI DMA:
>  -dma-channels: Number of dma channels in child node.
>  
> diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
> index 5eeea57..edb5b71 100644
> --- a/drivers/dma/xilinx/xilinx_dma.c
> +++ b/drivers/dma/xilinx/xilinx_dma.c
> @@ -322,6 +322,7 @@ struct xilinx_dma_tx_descriptor {
>   * @genlock: Support genlock mode
>   * @err: Channel has errors
>   * @idle: Check for channel idle
> + * @has_fstoreen: Check for frame store configuration
>   * @tasklet: Cleanup work after irq
>   * @config: Device configuration info
>   * @flush_on_fsync: Flush on Frame sync
> @@ -353,6 +354,7 @@ struct xilinx_dma_chan {
>   bool genlock;
>   bool err;
>   bool idle;
> + bool has_fstoreen;
>   struct tasklet_struct tasklet;
>   struct xilinx_vdma_config config;
>   bool flush_on_fsync;
> @@ -990,6 +992,27 @@ static void xilinx_vdma_start_transfer(struct 
> xilinx_dma_chan *chan)
>   if (list_empty(>pending_list))
>   return;
>  
> + /*
> +  * Note: When VDMA is built with default h/w configuration
> +  * User should submit frames upto H/W configured.
> +  * If users submits less than h/w configured
> +  * VDMA engine tries to write to a invalid location
> +  * Results undefined behaviour/memory corruption.
> +  *
> +  * If user would like to submit frames less than h/w capable
> +  * On S2MM side please enable debug info 13 at the h/w level
> +  * On MM2S side please enable debug info 6 at the h/w level
> +  * It will allows the frame buffers numbers to be modified at runtime.
> +  */
> + if (!chan->has_fstoreen &&
> +  chan->desc_pendingcount < chan->num_frms) {
> + dev_warn(chan->dev, "Frame Store Configuration is not enabled 
> at the\n");
> + dev_warn(chan->dev, "H/w level enable Debug info 13 or 6 at the 
> h/w level\n");
> + dev_warn(chan->dev, "OR Submit the frames upto h/w 
> Capable\n\r");
> +
> + return;
> + }
> +
>   desc = list_first_entry(>pending_list,
>   struct xilinx_dma_tx_descriptor, node);
>   tail_desc = list_last_entry(>pending_list,
> @@ -1052,25 +1075,38 @@ static void xilinx_vdma_start_transfer(struct 
> xilinx_dma_chan *chan)
>   if (chan->has_sg) {
>   dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
>   tail_segment->phys);
> + list_splice_tail_init(>pending_list, 

Re: [PATCH v6 2/3] dmaeninge: xilinx_dma: Fix bug in multiple frame stores scenario in vdma

[Vinod Koul]

On Sat, Jan 14, 2017 at 11:05:54AM +0530, Kedareswara rao Appana wrote:
> When VDMA is configured for more than one frame in the h/w.
> For example h/w is configured for n number of frames, user
> Submits n number of frames and triggered the DMA using issue_pending API.
> 
> In the current driver flow we are submitting one frame at a time,
> But we should submit all the n number of frames at one time
> As the h/w is configured for n number of frames.

Is there a specific reason why you continue to start lines with Title cases, I
have already told you to not do that last time!

> 
> This patch fixes this issue.
> 
> Acked-by: Rob Herring 
> Reviewed-by: Jose Abreu 
> Signed-off-by: Kedareswara rao Appana 
> ---
> Changes for v6:
> ---> Added Rob Acked-by
> ---> Updated commit message as suggested by Vinod.
> Changes for v5:
> ---> Updated xlnx,fstore-config property to xlnx,fstore-enable
>  and updated description as suggested by Rob.
> Changes for v4:
> ---> Add Check for framestore configuration on Transmit case as well
>  as suggested by Jose Abreu.
> ---> Modified the dev_dbg checks to dev_warn checks as suggested
>  by Jose Abreu.
> Changes for v3:
> ---> Added Checks for frame store configuration. If frame store
>  Configuration is not present at the h/w level and user
>  Submits less frames added debug prints in the driver as relevant.
> Changes for v2:
> ---> Fixed race conditions in the driver as suggested by Jose Abreu
> ---> Fixed unnecessray if else checks in the vdma_start_transfer
>  as suggested by Laurent Pinchart.
> 
>  .../devicetree/bindings/dma/xilinx/xilinx_dma.txt  |  2 +
>  drivers/dma/xilinx/xilinx_dma.c| 78 
> +++---
>  2 files changed, 57 insertions(+), 23 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt 
> b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
> index a2b8bfa..e951c09 100644
> --- a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
> +++ b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
> @@ -66,6 +66,8 @@ Optional child node properties:
>  Optional child node properties for VDMA:
>  - xlnx,genlock-mode: Tells Genlock synchronization is
>   enabled/disabled in hardware.
> +- xlnx,fstore-enable: boolean; if defined, it indicates that controller
> + supports frame store configuration.
>  Optional child node properties for AXI DMA:
>  -dma-channels: Number of dma channels in child node.
>  
> diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
> index 5eeea57..edb5b71 100644
> --- a/drivers/dma/xilinx/xilinx_dma.c
> +++ b/drivers/dma/xilinx/xilinx_dma.c
> @@ -322,6 +322,7 @@ struct xilinx_dma_tx_descriptor {
>   * @genlock: Support genlock mode
>   * @err: Channel has errors
>   * @idle: Check for channel idle
> + * @has_fstoreen: Check for frame store configuration
>   * @tasklet: Cleanup work after irq
>   * @config: Device configuration info
>   * @flush_on_fsync: Flush on Frame sync
> @@ -353,6 +354,7 @@ struct xilinx_dma_chan {
>   bool genlock;
>   bool err;
>   bool idle;
> + bool has_fstoreen;
>   struct tasklet_struct tasklet;
>   struct xilinx_vdma_config config;
>   bool flush_on_fsync;
> @@ -990,6 +992,27 @@ static void xilinx_vdma_start_transfer(struct 
> xilinx_dma_chan *chan)
>   if (list_empty(>pending_list))
>   return;
>  
> + /*
> +  * Note: When VDMA is built with default h/w configuration
> +  * User should submit frames upto H/W configured.
> +  * If users submits less than h/w configured
> +  * VDMA engine tries to write to a invalid location
> +  * Results undefined behaviour/memory corruption.
> +  *
> +  * If user would like to submit frames less than h/w capable
> +  * On S2MM side please enable debug info 13 at the h/w level
> +  * On MM2S side please enable debug info 6 at the h/w level
> +  * It will allows the frame buffers numbers to be modified at runtime.
> +  */
> + if (!chan->has_fstoreen &&
> +  chan->desc_pendingcount < chan->num_frms) {
> + dev_warn(chan->dev, "Frame Store Configuration is not enabled 
> at the\n");
> + dev_warn(chan->dev, "H/w level enable Debug info 13 or 6 at the 
> h/w level\n");
> + dev_warn(chan->dev, "OR Submit the frames upto h/w 
> Capable\n\r");
> +
> + return;
> + }
> +
>   desc = list_first_entry(>pending_list,
>   struct xilinx_dma_tx_descriptor, node);
>   tail_desc = list_last_entry(>pending_list,
> @@ -1052,25 +1075,38 @@ static void xilinx_vdma_start_transfer(struct 
> xilinx_dma_chan *chan)
>   if (chan->has_sg) {
>   dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
>   tail_segment->phys);
> + list_splice_tail_init(>pending_list, >active_list);
> + chan->desc_pendingcount = 0;

Re: [PATCH v6 2/3] dmaeninge: xilinx_dma: Fix bug in multiple frame stores scenario in vdma

[Mike Looijmans]

On 14-01-17 06:35, Kedareswara rao Appana wrote:

When VDMA is configured for more than one frame in the h/w.
For example h/w is configured for n number of frames, user
Submits n number of frames and triggered the DMA using issue_pending API.

In the current driver flow we are submitting one frame at a time,
But we should submit all the n number of frames at one time
As the h/w is configured for n number of frames.


The hardware can always handle a single frame submission, by using the "park" 
bit. This would make a good "cyclic" implementation too (using vdma as 
framebuffer).


It could also handle all cases for "k" frames where n%k==0 (n is a multiple of 
k) by simply replicating the frame pointers.




This patch fixes this issue.

Acked-by: Rob Herring 
Reviewed-by: Jose Abreu 
Signed-off-by: Kedareswara rao Appana 
---
Changes for v6:
---> Added Rob Acked-by
---> Updated commit message as suggested by Vinod.
Changes for v5:
---> Updated xlnx,fstore-config property to xlnx,fstore-enable
 and updated description as suggested by Rob.
Changes for v4:
---> Add Check for framestore configuration on Transmit case as well
 as suggested by Jose Abreu.
---> Modified the dev_dbg checks to dev_warn checks as suggested
 by Jose Abreu.
Changes for v3:
---> Added Checks for frame store configuration. If frame store
 Configuration is not present at the h/w level and user
 Submits less frames added debug prints in the driver as relevant.
Changes for v2:
---> Fixed race conditions in the driver as suggested by Jose Abreu
---> Fixed unnecessray if else checks in the vdma_start_transfer
 as suggested by Laurent Pinchart.

 .../devicetree/bindings/dma/xilinx/xilinx_dma.txt  |  2 +
 drivers/dma/xilinx/xilinx_dma.c| 78 +++---
 2 files changed, 57 insertions(+), 23 deletions(-)

diff --git a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt 
b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
index a2b8bfa..e951c09 100644
--- a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
+++ b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
@@ -66,6 +66,8 @@ Optional child node properties:
 Optional child node properties for VDMA:
 - xlnx,genlock-mode: Tells Genlock synchronization is
enabled/disabled in hardware.
+- xlnx,fstore-enable: boolean; if defined, it indicates that controller
+   supports frame store configuration.
 Optional child node properties for AXI DMA:
 -dma-channels: Number of dma channels in child node.

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 5eeea57..edb5b71 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -322,6 +322,7 @@ struct xilinx_dma_tx_descriptor {
  * @genlock: Support genlock mode
  * @err: Channel has errors
  * @idle: Check for channel idle
+ * @has_fstoreen: Check for frame store configuration
  * @tasklet: Cleanup work after irq
  * @config: Device configuration info
  * @flush_on_fsync: Flush on Frame sync
@@ -353,6 +354,7 @@ struct xilinx_dma_chan {
bool genlock;
bool err;
bool idle;
+   bool has_fstoreen;
struct tasklet_struct tasklet;
struct xilinx_vdma_config config;
bool flush_on_fsync;
@@ -990,6 +992,27 @@ static void xilinx_vdma_start_transfer(struct 
xilinx_dma_chan *chan)
if (list_empty(>pending_list))
return;

+   /*
+* Note: When VDMA is built with default h/w configuration
+* User should submit frames upto H/W configured.
+* If users submits less than h/w configured
+* VDMA engine tries to write to a invalid location
+* Results undefined behaviour/memory corruption.
+*
+* If user would like to submit frames less than h/w capable
+* On S2MM side please enable debug info 13 at the h/w level
+* On MM2S side please enable debug info 6 at the h/w level
+* It will allows the frame buffers numbers to be modified at runtime.
+*/
+   if (!chan->has_fstoreen &&
+chan->desc_pendingcount < chan->num_frms) {
+   dev_warn(chan->dev, "Frame Store Configuration is not enabled at 
the\n");
+   dev_warn(chan->dev, "H/w level enable Debug info 13 or 6 at the h/w 
level\n");
+   dev_warn(chan->dev, "OR Submit the frames upto h/w 
Capable\n\r");
+
+   return;
+   }
+
desc = list_first_entry(>pending_list,
struct xilinx_dma_tx_descriptor, node);
tail_desc = list_last_entry(>pending_list,
@@ -1052,25 +1075,38 @@ static void xilinx_vdma_start_transfer(struct 
xilinx_dma_chan *chan)
if (chan->has_sg) {
dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
tail_segment->phys);
+   list_splice_tail_init(>pending_list, 

Re: [PATCH v6 2/3] dmaeninge: xilinx_dma: Fix bug in multiple frame stores scenario in vdma

[Mike Looijmans]

On 14-01-17 06:35, Kedareswara rao Appana wrote:

When VDMA is configured for more than one frame in the h/w.
For example h/w is configured for n number of frames, user
Submits n number of frames and triggered the DMA using issue_pending API.

In the current driver flow we are submitting one frame at a time,
But we should submit all the n number of frames at one time
As the h/w is configured for n number of frames.


The hardware can always handle a single frame submission, by using the "park" 
bit. This would make a good "cyclic" implementation too (using vdma as 
framebuffer).


It could also handle all cases for "k" frames where n%k==0 (n is a multiple of 
k) by simply replicating the frame pointers.




This patch fixes this issue.

Acked-by: Rob Herring 
Reviewed-by: Jose Abreu 
Signed-off-by: Kedareswara rao Appana 
---
Changes for v6:
---> Added Rob Acked-by
---> Updated commit message as suggested by Vinod.
Changes for v5:
---> Updated xlnx,fstore-config property to xlnx,fstore-enable
 and updated description as suggested by Rob.
Changes for v4:
---> Add Check for framestore configuration on Transmit case as well
 as suggested by Jose Abreu.
---> Modified the dev_dbg checks to dev_warn checks as suggested
 by Jose Abreu.
Changes for v3:
---> Added Checks for frame store configuration. If frame store
 Configuration is not present at the h/w level and user
 Submits less frames added debug prints in the driver as relevant.
Changes for v2:
---> Fixed race conditions in the driver as suggested by Jose Abreu
---> Fixed unnecessray if else checks in the vdma_start_transfer
 as suggested by Laurent Pinchart.

 .../devicetree/bindings/dma/xilinx/xilinx_dma.txt  |  2 +
 drivers/dma/xilinx/xilinx_dma.c| 78 +++---
 2 files changed, 57 insertions(+), 23 deletions(-)

diff --git a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt 
b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
index a2b8bfa..e951c09 100644
--- a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
+++ b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
@@ -66,6 +66,8 @@ Optional child node properties:
 Optional child node properties for VDMA:
 - xlnx,genlock-mode: Tells Genlock synchronization is
enabled/disabled in hardware.
+- xlnx,fstore-enable: boolean; if defined, it indicates that controller
+   supports frame store configuration.
 Optional child node properties for AXI DMA:
 -dma-channels: Number of dma channels in child node.

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 5eeea57..edb5b71 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -322,6 +322,7 @@ struct xilinx_dma_tx_descriptor {
  * @genlock: Support genlock mode
  * @err: Channel has errors
  * @idle: Check for channel idle
+ * @has_fstoreen: Check for frame store configuration
  * @tasklet: Cleanup work after irq
  * @config: Device configuration info
  * @flush_on_fsync: Flush on Frame sync
@@ -353,6 +354,7 @@ struct xilinx_dma_chan {
bool genlock;
bool err;
bool idle;
+   bool has_fstoreen;
struct tasklet_struct tasklet;
struct xilinx_vdma_config config;
bool flush_on_fsync;
@@ -990,6 +992,27 @@ static void xilinx_vdma_start_transfer(struct 
xilinx_dma_chan *chan)
if (list_empty(>pending_list))
return;

+   /*
+* Note: When VDMA is built with default h/w configuration
+* User should submit frames upto H/W configured.
+* If users submits less than h/w configured
+* VDMA engine tries to write to a invalid location
+* Results undefined behaviour/memory corruption.
+*
+* If user would like to submit frames less than h/w capable
+* On S2MM side please enable debug info 13 at the h/w level
+* On MM2S side please enable debug info 6 at the h/w level
+* It will allows the frame buffers numbers to be modified at runtime.
+*/
+   if (!chan->has_fstoreen &&
+chan->desc_pendingcount < chan->num_frms) {
+   dev_warn(chan->dev, "Frame Store Configuration is not enabled at 
the\n");
+   dev_warn(chan->dev, "H/w level enable Debug info 13 or 6 at the h/w 
level\n");
+   dev_warn(chan->dev, "OR Submit the frames upto h/w 
Capable\n\r");
+
+   return;
+   }
+
desc = list_first_entry(>pending_list,
struct xilinx_dma_tx_descriptor, node);
tail_desc = list_last_entry(>pending_list,
@@ -1052,25 +1075,38 @@ static void xilinx_vdma_start_transfer(struct 
xilinx_dma_chan *chan)
if (chan->has_sg) {
dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
tail_segment->phys);
+   list_splice_tail_init(>pending_list, >active_list);
+   chan->desc_pendingcount = 0;

[PATCH v6 2/3] dmaeninge: xilinx_dma: Fix bug in multiple frame stores scenario in vdma

[Kedareswara rao Appana]

When VDMA is configured for more than one frame in the h/w.
For example h/w is configured for n number of frames, user
Submits n number of frames and triggered the DMA using issue_pending API.

In the current driver flow we are submitting one frame at a time,
But we should submit all the n number of frames at one time
As the h/w is configured for n number of frames.

This patch fixes this issue.

Acked-by: Rob Herring 
Reviewed-by: Jose Abreu 
Signed-off-by: Kedareswara rao Appana 
---
Changes for v6:
---> Added Rob Acked-by
---> Updated commit message as suggested by Vinod.
Changes for v5:
---> Updated xlnx,fstore-config property to xlnx,fstore-enable
 and updated description as suggested by Rob.
Changes for v4:
---> Add Check for framestore configuration on Transmit case as well
 as suggested by Jose Abreu.
---> Modified the dev_dbg checks to dev_warn checks as suggested
 by Jose Abreu.
Changes for v3:
---> Added Checks for frame store configuration. If frame store
 Configuration is not present at the h/w level and user
 Submits less frames added debug prints in the driver as relevant.
Changes for v2:
---> Fixed race conditions in the driver as suggested by Jose Abreu
---> Fixed unnecessray if else checks in the vdma_start_transfer
 as suggested by Laurent Pinchart.

 .../devicetree/bindings/dma/xilinx/xilinx_dma.txt  |  2 +
 drivers/dma/xilinx/xilinx_dma.c| 78 +++---
 2 files changed, 57 insertions(+), 23 deletions(-)

diff --git a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt 
b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
index a2b8bfa..e951c09 100644
--- a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
+++ b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
@@ -66,6 +66,8 @@ Optional child node properties:
 Optional child node properties for VDMA:
 - xlnx,genlock-mode: Tells Genlock synchronization is
enabled/disabled in hardware.
+- xlnx,fstore-enable: boolean; if defined, it indicates that controller
+   supports frame store configuration.
 Optional child node properties for AXI DMA:
 -dma-channels: Number of dma channels in child node.
 
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 5eeea57..edb5b71 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -322,6 +322,7 @@ struct xilinx_dma_tx_descriptor {
  * @genlock: Support genlock mode
  * @err: Channel has errors
  * @idle: Check for channel idle
+ * @has_fstoreen: Check for frame store configuration
  * @tasklet: Cleanup work after irq
  * @config: Device configuration info
  * @flush_on_fsync: Flush on Frame sync
@@ -353,6 +354,7 @@ struct xilinx_dma_chan {
bool genlock;
bool err;
bool idle;
+   bool has_fstoreen;
struct tasklet_struct tasklet;
struct xilinx_vdma_config config;
bool flush_on_fsync;
@@ -990,6 +992,27 @@ static void xilinx_vdma_start_transfer(struct 
xilinx_dma_chan *chan)
if (list_empty(>pending_list))
return;
 
+   /*
+* Note: When VDMA is built with default h/w configuration
+* User should submit frames upto H/W configured.
+* If users submits less than h/w configured
+* VDMA engine tries to write to a invalid location
+* Results undefined behaviour/memory corruption.
+*
+* If user would like to submit frames less than h/w capable
+* On S2MM side please enable debug info 13 at the h/w level
+* On MM2S side please enable debug info 6 at the h/w level
+* It will allows the frame buffers numbers to be modified at runtime.
+*/
+   if (!chan->has_fstoreen &&
+chan->desc_pendingcount < chan->num_frms) {
+   dev_warn(chan->dev, "Frame Store Configuration is not enabled 
at the\n");
+   dev_warn(chan->dev, "H/w level enable Debug info 13 or 6 at the 
h/w level\n");
+   dev_warn(chan->dev, "OR Submit the frames upto h/w 
Capable\n\r");
+
+   return;
+   }
+
desc = list_first_entry(>pending_list,
struct xilinx_dma_tx_descriptor, node);
tail_desc = list_last_entry(>pending_list,
@@ -1052,25 +1075,38 @@ static void xilinx_vdma_start_transfer(struct 
xilinx_dma_chan *chan)
if (chan->has_sg) {
dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
tail_segment->phys);
+   list_splice_tail_init(>pending_list, >active_list);
+   chan->desc_pendingcount = 0;
} else {
struct xilinx_vdma_tx_segment *segment, *last = NULL;
-   int i = 0;
+   int i = 0, j = 0;
 
if (chan->desc_submitcount < chan->num_frms)
i = chan->desc_submitcount;
 
-   

[PATCH v6 2/3] dmaeninge: xilinx_dma: Fix bug in multiple frame stores scenario in vdma

[Kedareswara rao Appana]

When VDMA is configured for more than one frame in the h/w.
For example h/w is configured for n number of frames, user
Submits n number of frames and triggered the DMA using issue_pending API.

In the current driver flow we are submitting one frame at a time,
But we should submit all the n number of frames at one time
As the h/w is configured for n number of frames.

This patch fixes this issue.

Acked-by: Rob Herring 
Reviewed-by: Jose Abreu 
Signed-off-by: Kedareswara rao Appana 
---
Changes for v6:
---> Added Rob Acked-by
---> Updated commit message as suggested by Vinod.
Changes for v5:
---> Updated xlnx,fstore-config property to xlnx,fstore-enable
 and updated description as suggested by Rob.
Changes for v4:
---> Add Check for framestore configuration on Transmit case as well
 as suggested by Jose Abreu.
---> Modified the dev_dbg checks to dev_warn checks as suggested
 by Jose Abreu.
Changes for v3:
---> Added Checks for frame store configuration. If frame store
 Configuration is not present at the h/w level and user
 Submits less frames added debug prints in the driver as relevant.
Changes for v2:
---> Fixed race conditions in the driver as suggested by Jose Abreu
---> Fixed unnecessray if else checks in the vdma_start_transfer
 as suggested by Laurent Pinchart.

 .../devicetree/bindings/dma/xilinx/xilinx_dma.txt  |  2 +
 drivers/dma/xilinx/xilinx_dma.c| 78 +++---
 2 files changed, 57 insertions(+), 23 deletions(-)

diff --git a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt 
b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
index a2b8bfa..e951c09 100644
--- a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
+++ b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
@@ -66,6 +66,8 @@ Optional child node properties:
 Optional child node properties for VDMA:
 - xlnx,genlock-mode: Tells Genlock synchronization is
enabled/disabled in hardware.
+- xlnx,fstore-enable: boolean; if defined, it indicates that controller
+   supports frame store configuration.
 Optional child node properties for AXI DMA:
 -dma-channels: Number of dma channels in child node.
 
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 5eeea57..edb5b71 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -322,6 +322,7 @@ struct xilinx_dma_tx_descriptor {
  * @genlock: Support genlock mode
  * @err: Channel has errors
  * @idle: Check for channel idle
+ * @has_fstoreen: Check for frame store configuration
  * @tasklet: Cleanup work after irq
  * @config: Device configuration info
  * @flush_on_fsync: Flush on Frame sync
@@ -353,6 +354,7 @@ struct xilinx_dma_chan {
bool genlock;
bool err;
bool idle;
+   bool has_fstoreen;
struct tasklet_struct tasklet;
struct xilinx_vdma_config config;
bool flush_on_fsync;
@@ -990,6 +992,27 @@ static void xilinx_vdma_start_transfer(struct 
xilinx_dma_chan *chan)
if (list_empty(>pending_list))
return;
 
+   /*
+* Note: When VDMA is built with default h/w configuration
+* User should submit frames upto H/W configured.
+* If users submits less than h/w configured
+* VDMA engine tries to write to a invalid location
+* Results undefined behaviour/memory corruption.
+*
+* If user would like to submit frames less than h/w capable
+* On S2MM side please enable debug info 13 at the h/w level
+* On MM2S side please enable debug info 6 at the h/w level
+* It will allows the frame buffers numbers to be modified at runtime.
+*/
+   if (!chan->has_fstoreen &&
+chan->desc_pendingcount < chan->num_frms) {
+   dev_warn(chan->dev, "Frame Store Configuration is not enabled 
at the\n");
+   dev_warn(chan->dev, "H/w level enable Debug info 13 or 6 at the 
h/w level\n");
+   dev_warn(chan->dev, "OR Submit the frames upto h/w 
Capable\n\r");
+
+   return;
+   }
+
desc = list_first_entry(>pending_list,
struct xilinx_dma_tx_descriptor, node);
tail_desc = list_last_entry(>pending_list,
@@ -1052,25 +1075,38 @@ static void xilinx_vdma_start_transfer(struct 
xilinx_dma_chan *chan)
if (chan->has_sg) {
dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
tail_segment->phys);
+   list_splice_tail_init(>pending_list, >active_list);
+   chan->desc_pendingcount = 0;
} else {
struct xilinx_vdma_tx_segment *segment, *last = NULL;
-   int i = 0;
+   int i = 0, j = 0;
 
if (chan->desc_submitcount < chan->num_frms)
i = chan->desc_submitcount;
 
-   list_for_each_entry(segment, >segments, node) {
-