Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
Hi Greg,
On 2021/12/13 8:50, Lu Baolu wrote:
On 12/10/21 9:23 AM, Lu Baolu wrote:
Hi Greg, Jason and Christoph,
On 12/9/21 9:20 AM, Lu Baolu wrote:
On 12/7/21 9:16 PM, Jason Gunthorpe wrote:
On Tue, Dec 07, 2021 at 10:57:25AM +0800, Lu Baolu wrote:
On 12/6/21 11:06 PM, Jason Gunthorpe wrote:
On Mon, Dec 06, 2021 at 06:36:27AM -0800, Christoph Hellwig wrote:
I really hate the amount of boilerplate code that having this in
each
bus type causes.
+1
I liked the first version of this series better with the code near
really_probe().
Can we go back to that with some device_configure_dma() wrapper
condtionally called by really_probe as we discussed?
[...]
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 68ea1f949daa..68ca5a579eb1 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -538,6 +538,32 @@ static int call_driver_probe(struct device *dev,
struct device_driver *drv)
return ret;
}
+static int device_dma_configure(struct device *dev, struct
device_driver *drv)
+{
+ int ret;
+
+ if (!dev->bus->dma_configure)
+ return 0;
+
+ ret = dev->bus->dma_configure(dev);
+ if (ret)
+ return ret;
+
+ if (!drv->suppress_auto_claim_dma_owner)
+ ret = iommu_device_set_dma_owner(dev,
DMA_OWNER_DMA_API, NULL);
+
+ return ret;
+}
+
+static void device_dma_cleanup(struct device *dev, struct
device_driver *drv)
+{
+ if (!dev->bus->dma_configure)
+ return;
+
+ if (!drv->suppress_auto_claim_dma_owner)
+ iommu_device_release_dma_owner(dev, DMA_OWNER_DMA_API);
+}
+
static int really_probe(struct device *dev, struct device_driver *drv)
{
bool test_remove =
IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
@@ -574,11 +600,8 @@ static int really_probe(struct device *dev,
struct device_driver *drv)
if (ret)
goto pinctrl_bind_failed;
- if (dev->bus->dma_configure) {
- ret = dev->bus->dma_configure(dev);
- if (ret)
- goto probe_failed;
- }
+ if (device_dma_configure(dev, drv))
+ goto pinctrl_bind_failed;
ret = driver_sysfs_add(dev);
if (ret) {
@@ -660,6 +683,8 @@ static int really_probe(struct device *dev,
struct device_driver *drv)
if (dev->bus)
blocking_notifier_call_chain(>bus->p->bus_notifier,
BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
+
+ device_dma_cleanup(dev, drv);
pinctrl_bind_failed:
device_links_no_driver(dev);
devres_release_all(dev);
@@ -1204,6 +1229,7 @@ static void __device_release_driver(struct
device *dev, struct device *parent)
else if (drv->remove)
drv->remove(dev);
+ device_dma_cleanup(dev, drv);
device_links_driver_cleanup(dev);
devres_release_all(dev);
diff --git a/include/linux/device/driver.h
b/include/linux/device/driver.h
index a498ebcf4993..374a3c2cc10d 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -100,6 +100,7 @@ struct device_driver {
const char *mod_name; /* used for built-in
modules */
bool suppress_bind_attrs; /* disables bind/unbind via
sysfs */
+ bool suppress_auto_claim_dma_owner;
enum probe_type probe_type;
const struct of_device_id *of_match_table;
Does this work for you? Can I work towards this in the next version?
A kindly ping ... Is this heading the right direction? I need your
advice to move ahead. :-)
Can I do it like this? :-)
Best regards,
baolu
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Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
This approach looks much better to me. ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
On Mon, Dec 13, 2021 at 08:50:05AM +0800, Lu Baolu wrote: > > Does this work for you? Can I work towards this in the next version? > > A kindly ping ... Is this heading the right direction? I need your > advice to move ahead. :-) I prefer this to all the duplicated code in the v3 series.. Given it touches almost every bus type that implements the dma_configure it seems appropriate. Jason ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
On 12/10/21 9:23 AM, Lu Baolu wrote:
Hi Greg, Jason and Christoph,
On 12/9/21 9:20 AM, Lu Baolu wrote:
On 12/7/21 9:16 PM, Jason Gunthorpe wrote:
On Tue, Dec 07, 2021 at 10:57:25AM +0800, Lu Baolu wrote:
On 12/6/21 11:06 PM, Jason Gunthorpe wrote:
On Mon, Dec 06, 2021 at 06:36:27AM -0800, Christoph Hellwig wrote:
I really hate the amount of boilerplate code that having this in each
bus type causes.
+1
I liked the first version of this series better with the code near
really_probe().
Can we go back to that with some device_configure_dma() wrapper
condtionally called by really_probe as we discussed?
[...]
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 68ea1f949daa..68ca5a579eb1 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -538,6 +538,32 @@ static int call_driver_probe(struct device *dev,
struct device_driver *drv)
return ret;
}
+static int device_dma_configure(struct device *dev, struct
device_driver *drv)
+{
+ int ret;
+
+ if (!dev->bus->dma_configure)
+ return 0;
+
+ ret = dev->bus->dma_configure(dev);
+ if (ret)
+ return ret;
+
+ if (!drv->suppress_auto_claim_dma_owner)
+ ret = iommu_device_set_dma_owner(dev,
DMA_OWNER_DMA_API, NULL);
+
+ return ret;
+}
+
+static void device_dma_cleanup(struct device *dev, struct
device_driver *drv)
+{
+ if (!dev->bus->dma_configure)
+ return;
+
+ if (!drv->suppress_auto_claim_dma_owner)
+ iommu_device_release_dma_owner(dev, DMA_OWNER_DMA_API);
+}
+
static int really_probe(struct device *dev, struct device_driver *drv)
{
bool test_remove =
IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
@@ -574,11 +600,8 @@ static int really_probe(struct device *dev,
struct device_driver *drv)
if (ret)
goto pinctrl_bind_failed;
- if (dev->bus->dma_configure) {
- ret = dev->bus->dma_configure(dev);
- if (ret)
- goto probe_failed;
- }
+ if (device_dma_configure(dev, drv))
+ goto pinctrl_bind_failed;
ret = driver_sysfs_add(dev);
if (ret) {
@@ -660,6 +683,8 @@ static int really_probe(struct device *dev, struct
device_driver *drv)
if (dev->bus)
blocking_notifier_call_chain(>bus->p->bus_notifier,
BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
+
+ device_dma_cleanup(dev, drv);
pinctrl_bind_failed:
device_links_no_driver(dev);
devres_release_all(dev);
@@ -1204,6 +1229,7 @@ static void __device_release_driver(struct
device *dev, struct device *parent)
else if (drv->remove)
drv->remove(dev);
+ device_dma_cleanup(dev, drv);
device_links_driver_cleanup(dev);
devres_release_all(dev);
diff --git a/include/linux/device/driver.h
b/include/linux/device/driver.h
index a498ebcf4993..374a3c2cc10d 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -100,6 +100,7 @@ struct device_driver {
const char *mod_name; /* used for built-in
modules */
bool suppress_bind_attrs; /* disables bind/unbind via
sysfs */
+ bool suppress_auto_claim_dma_owner;
enum probe_type probe_type;
const struct of_device_id *of_match_table;
Does this work for you? Can I work towards this in the next version?
A kindly ping ... Is this heading the right direction? I need your
advice to move ahead. :-)
Best regards,
baolu
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Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
Hi Greg, Jason and Christoph,
On 12/9/21 9:20 AM, Lu Baolu wrote:
On 12/7/21 9:16 PM, Jason Gunthorpe wrote:
On Tue, Dec 07, 2021 at 10:57:25AM +0800, Lu Baolu wrote:
On 12/6/21 11:06 PM, Jason Gunthorpe wrote:
On Mon, Dec 06, 2021 at 06:36:27AM -0800, Christoph Hellwig wrote:
I really hate the amount of boilerplate code that having this in each
bus type causes.
+1
I liked the first version of this series better with the code near
really_probe().
Can we go back to that with some device_configure_dma() wrapper
condtionally called by really_probe as we discussed?
[...]
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 68ea1f949daa..68ca5a579eb1 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -538,6 +538,32 @@ static int call_driver_probe(struct device *dev,
struct device_driver *drv)
return ret;
}
+static int device_dma_configure(struct device *dev, struct
device_driver *drv)
+{
+ int ret;
+
+ if (!dev->bus->dma_configure)
+ return 0;
+
+ ret = dev->bus->dma_configure(dev);
+ if (ret)
+ return ret;
+
+ if (!drv->suppress_auto_claim_dma_owner)
+ ret = iommu_device_set_dma_owner(dev, DMA_OWNER_DMA_API,
NULL);
+
+ return ret;
+}
+
+static void device_dma_cleanup(struct device *dev, struct device_driver
*drv)
+{
+ if (!dev->bus->dma_configure)
+ return;
+
+ if (!drv->suppress_auto_claim_dma_owner)
+ iommu_device_release_dma_owner(dev, DMA_OWNER_DMA_API,
NULL);
+}
+
static int really_probe(struct device *dev, struct device_driver *drv)
{
bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
@@ -574,11 +600,8 @@ static int really_probe(struct device *dev, struct
device_driver *drv)
if (ret)
goto pinctrl_bind_failed;
- if (dev->bus->dma_configure) {
- ret = dev->bus->dma_configure(dev);
- if (ret)
- goto probe_failed;
- }
+ if (device_dma_configure(dev, drv))
+ goto pinctrl_bind_failed;
ret = driver_sysfs_add(dev);
if (ret) {
@@ -660,6 +683,8 @@ static int really_probe(struct device *dev, struct
device_driver *drv)
if (dev->bus)
blocking_notifier_call_chain(>bus->p->bus_notifier,
BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
+
+ device_dma_cleanup(dev, drv);
pinctrl_bind_failed:
device_links_no_driver(dev);
devres_release_all(dev);
@@ -1204,6 +1229,7 @@ static void __device_release_driver(struct device
*dev, struct device *parent)
else if (drv->remove)
drv->remove(dev);
+ device_dma_cleanup(dev, drv);
device_links_driver_cleanup(dev);
devres_release_all(dev);
diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h
index a498ebcf4993..374a3c2cc10d 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -100,6 +100,7 @@ struct device_driver {
const char *mod_name; /* used for built-in
modules */
bool suppress_bind_attrs; /* disables bind/unbind via
sysfs */
+ bool suppress_auto_claim_dma_owner;
enum probe_type probe_type;
const struct of_device_id *of_match_table;
Does this work for you? Can I work towards this in the next version?
Best regards,
baolu
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Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
On 12/7/21 9:16 PM, Jason Gunthorpe wrote:
On Tue, Dec 07, 2021 at 10:57:25AM +0800, Lu Baolu wrote:
On 12/6/21 11:06 PM, Jason Gunthorpe wrote:
On Mon, Dec 06, 2021 at 06:36:27AM -0800, Christoph Hellwig wrote:
I really hate the amount of boilerplate code that having this in each
bus type causes.
+1
I liked the first version of this series better with the code near
really_probe().
Can we go back to that with some device_configure_dma() wrapper
condtionally called by really_probe as we discussed?
Are you talking about below change?
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 68ea1f949daa..368f9e530515 100644
+++ b/drivers/base/dd.c
@@ -577,7 +577,13 @@ static int really_probe(struct device *dev, struct
device_driver *drv)
if (dev->bus->dma_configure) {
ret = dev->bus->dma_configure(dev);
if (ret)
- goto probe_failed;
+ goto pinctrl_bind_failed;
+
+ if (!drv->no_kernel_dma) {
+ ret = iommu_device_set_dma_owner(dev,
DMA_OWNER_DMA_API, NULL);
+ if (ret)
+ goto pinctrl_bind_failed;
+}
}
Yes, the suggestion was to put everything that 'if' inside a function
and then of course a matching undo function.
Followed your suggestion, I refactored the change like below:
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 68ea1f949daa..68ca5a579eb1 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -538,6 +538,32 @@ static int call_driver_probe(struct device *dev,
struct device_driver *drv)
return ret;
}
+static int device_dma_configure(struct device *dev, struct
device_driver *drv)
+{
+ int ret;
+
+ if (!dev->bus->dma_configure)
+ return 0;
+
+ ret = dev->bus->dma_configure(dev);
+ if (ret)
+ return ret;
+
+ if (!drv->suppress_auto_claim_dma_owner)
+ ret = iommu_device_set_dma_owner(dev, DMA_OWNER_DMA_API,
NULL);
+
+ return ret;
+}
+
+static void device_dma_cleanup(struct device *dev, struct device_driver
*drv)
+{
+ if (!dev->bus->dma_configure)
+ return;
+
+ if (!drv->suppress_auto_claim_dma_owner)
+ iommu_device_release_dma_owner(dev, DMA_OWNER_DMA_API,
NULL);
+}
+
static int really_probe(struct device *dev, struct device_driver *drv)
{
bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
@@ -574,11 +600,8 @@ static int really_probe(struct device *dev, struct
device_driver *drv)
if (ret)
goto pinctrl_bind_failed;
- if (dev->bus->dma_configure) {
- ret = dev->bus->dma_configure(dev);
- if (ret)
- goto probe_failed;
- }
+ if (device_dma_configure(dev, drv))
+ goto pinctrl_bind_failed;
ret = driver_sysfs_add(dev);
if (ret) {
@@ -660,6 +683,8 @@ static int really_probe(struct device *dev, struct
device_driver *drv)
if (dev->bus)
blocking_notifier_call_chain(>bus->p->bus_notifier,
BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
+
+ device_dma_cleanup(dev, drv);
pinctrl_bind_failed:
device_links_no_driver(dev);
devres_release_all(dev);
@@ -1204,6 +1229,7 @@ static void __device_release_driver(struct device
*dev, struct device *parent)
else if (drv->remove)
drv->remove(dev);
+ device_dma_cleanup(dev, drv);
device_links_driver_cleanup(dev);
devres_release_all(dev);
diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h
index a498ebcf4993..374a3c2cc10d 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -100,6 +100,7 @@ struct device_driver {
const char *mod_name; /* used for built-in
modules */
bool suppress_bind_attrs; /* disables bind/unbind via
sysfs */
+ bool suppress_auto_claim_dma_owner;
enum probe_type probe_type;
const struct of_device_id *of_match_table;
Further suggestions?
Best regards,
baolu
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Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
On Tue, Dec 07, 2021 at 05:25:04AM -0800, Christoph Hellwig wrote: > On Tue, Dec 07, 2021 at 09:16:27AM -0400, Jason Gunthorpe wrote: > > Yes, the suggestion was to put everything that 'if' inside a function > > and then of course a matching undo function. > > Can't we simplify things even more? Do away with the DMA API owner > entirely, and instead in iommu_group_set_dma_owner iterate over all > devices in a group and check that they all have the no_dma_api flag > set (plus a similar check on group join). With that most of the > boilerplate code goes away entirely in favor of a little more work at > iommu_group_set_dma_owner time. Robin suggested something like this already. The locking doesn't work out, we can't nest device_lock()'s safely without ABBA deadlocks, and can't touch the dev->driver without the device_lock. Jason ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
On Tue, Dec 07, 2021 at 09:16:27AM -0400, Jason Gunthorpe wrote: > Yes, the suggestion was to put everything that 'if' inside a function > and then of course a matching undo function. Can't we simplify things even more? Do away with the DMA API owner entirely, and instead in iommu_group_set_dma_owner iterate over all devices in a group and check that they all have the no_dma_api flag set (plus a similar check on group join). With that most of the boilerplate code goes away entirely in favor of a little more work at iommu_group_set_dma_owner time. ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
On Tue, Dec 07, 2021 at 10:57:25AM +0800, Lu Baolu wrote:
> On 12/6/21 11:06 PM, Jason Gunthorpe wrote:
> > On Mon, Dec 06, 2021 at 06:36:27AM -0800, Christoph Hellwig wrote:
> > > I really hate the amount of boilerplate code that having this in each
> > > bus type causes.
> > +1
> >
> > I liked the first version of this series better with the code near
> > really_probe().
> >
> > Can we go back to that with some device_configure_dma() wrapper
> > condtionally called by really_probe as we discussed?
> >
>
> Are you talking about below change?
>
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index 68ea1f949daa..368f9e530515 100644
> +++ b/drivers/base/dd.c
> @@ -577,7 +577,13 @@ static int really_probe(struct device *dev, struct
> device_driver *drv)
> if (dev->bus->dma_configure) {
> ret = dev->bus->dma_configure(dev);
> if (ret)
> - goto probe_failed;
> + goto pinctrl_bind_failed;
> +
> + if (!drv->no_kernel_dma) {
> + ret = iommu_device_set_dma_owner(dev,
> DMA_OWNER_DMA_API, NULL);
> + if (ret)
> + goto pinctrl_bind_failed;
> +}
> }
Yes, the suggestion was to put everything that 'if' inside a function
and then of course a matching undo function.
Jason
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Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
On 12/6/21 11:06 PM, Jason Gunthorpe wrote:
On Mon, Dec 06, 2021 at 06:36:27AM -0800, Christoph Hellwig wrote:
I really hate the amount of boilerplate code that having this in each
bus type causes.
+1
I liked the first version of this series better with the code near
really_probe().
Can we go back to that with some device_configure_dma() wrapper
condtionally called by really_probe as we discussed?
Are you talking about below change?
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 68ea1f949daa..368f9e530515 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -577,7 +577,13 @@ static int really_probe(struct device *dev, struct
device_driver *drv)
if (dev->bus->dma_configure) {
ret = dev->bus->dma_configure(dev);
if (ret)
- goto probe_failed;
+ goto pinctrl_bind_failed;
+
+ if (!drv->no_kernel_dma) {
+ ret = iommu_device_set_dma_owner(dev,
DMA_OWNER_DMA_API, NULL);
+ if (ret)
+ goto pinctrl_bind_failed;
+}
}
ret = driver_sysfs_add(dev);
@@ -660,6 +666,9 @@ static int really_probe(struct device *dev, struct
device_driver *drv)
if (dev->bus)
blocking_notifier_call_chain(>bus->p->bus_notifier,
BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
+
+ if (dev->bus->dma_configure && !drv->no_kernel_dma)
+ iommu_device_release_dma_owner(dev, DMA_OWNER_DMA_API);
pinctrl_bind_failed:
device_links_no_driver(dev);
devres_release_all(dev);
@@ -1204,6 +1213,9 @@ static void __device_release_driver(struct device
*dev, struct device *parent)
else if (drv->remove)
drv->remove(dev);
+ if (dev->bus->dma_configure && !drv->no_kernel_dma)
+ iommu_device_release_dma_owner(dev, DMA_OWNER_DMA_API);
+
device_links_driver_cleanup(dev);
devres_release_all(dev);
diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h
index a498ebcf4993..2cf7b757b28e 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -100,6 +100,7 @@ struct device_driver {
const char *mod_name; /* used for built-in modules */
bool suppress_bind_attrs; /* disables bind/unbind via sysfs */
+ bool no_kernel_dma;
enum probe_type probe_type;
const struct of_device_id *of_match_table;
Best regards,
baolu
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Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
On Mon, Dec 06, 2021 at 06:36:27AM -0800, Christoph Hellwig wrote: > I really hate the amount of boilerplate code that having this in each > bus type causes. +1 I liked the first version of this series better with the code near really_probe(). Can we go back to that with some device_configure_dma() wrapper condtionally called by really_probe as we discussed? > Between that and the suggestion from Joerg I wonder if we could do the > following again: > > - add new no_kernel_dma flag to struct device_driver > - set this flag for the various vfio drivers > - skip claiming the kernel dma ownership for those (or rather release >it if the suggestion from Joerg works out) v1 did exactly this. Jason ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
I really hate the amount of boilerplate code that having this in each bus type causes. Between that and the suggestion from Joerg I wonder if we could do the following again: - add new no_kernel_dma flag to struct device_driver - set this flag for the various vfio drivers - skip claiming the kernel dma ownership for those (or rather release it if the suggestion from Joerg works out) ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management
On Mon, Dec 06, 2021 at 09:58:49AM +0800, Lu Baolu wrote:
> Multiple platform devices may be placed in the same IOMMU group because
> they cannot be isolated from each other. These devices must either be
> entirely under kernel control or userspace control, never a mixture. This
> checks and sets DMA ownership during driver binding, and release the
> ownership during driver unbinding.
>
> Driver may set a new flag (suppress_auto_claim_dma_owner) to disable auto
> claiming DMA_OWNER_DMA_API ownership in the binding process. For instance,
> the userspace framework drivers (vfio etc.) which need to manually claim
> DMA_OWNER_PRIVATE_DOMAIN_USER when assigning a device to userspace.
>
> Signed-off-by: Lu Baolu
> ---
> include/linux/platform_device.h | 1 +
> drivers/base/platform.c | 30 +-
> 2 files changed, 30 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
> index 4381c34af7e0..f3926be7582f 100644
> --- a/include/linux/platform_device.h
> +++ b/include/linux/platform_device.h
> @@ -210,6 +210,7 @@ struct platform_driver {
> struct device_driver driver;
> const struct platform_device_id *id_table;
> bool prevent_deferred_probe;
> + bool suppress_auto_claim_dma_owner;
We now have "prevent_" and "suppress_" as prefixes. Why the difference?
What is wrong with "prevent_" for your new flag?
thanks,
greg k-h
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