Re: [PATCH v3] mailbox: PCC: Fix lockdep warning when request PCC channel
Hi,
On Sun, Nov 13, 2016 at 11:44 AM, Prakash, Prashanth
wrote:
> HI Hoan,
>
> On 11/9/2016 11:39 PM, Hoan Tran wrote:
>> Hi All,
>>
>> On Thu, Oct 27, 2016 at 3:34 PM, Hoan Tran wrote:
>>> This patch fixes the lockdep warning below
>>>
>>> [7.229767] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
>>> [7.229776] [ cut here ]
>>> [7.229787] WARNING: CPU: 1 PID: 1 at
>>> linux-next/kernel/locking/lockdep.c:2876 loc
>>> kdep_trace_alloc+0xe0/0xf0
>>> [7.229790] Modules linked in:
>>> [7.229793]
>>> [7.229798] CPU: 1 PID: 1 Comm: swapper/0 Not tainted
>>> 4.8.0-11756-g86c5152 #46
>>> ...
>>> [7.229900] Call trace:
>>> [7.229903] Exception stack(0x8007da837890 to 0x8007da8379c0)
>>> [7.229906] 7880: 8007da834000
>>> 0001
>>> [7.229909] 78a0: 8007da837a70 08a0 60c5
>>> 003d
>>> [7.229912] 78c0: 9374bc6a7f3c7832 00381878 09db7ab8
>>> 002f
>>> [7.229915] 78e0: 0811aabc 08be2548 8007da837990
>>> 0811adf8
>>> [7.229918] 7900: 8007da834000 024080c0 00c0
>>> 09021000
>>> [7.229921] 7920: 08c8f7c8
>>> 8007da579810
>>> [7.229923] 7940: 002f 8007da858000
>>> 0001
>>> [7.229926] 7960: 0001 0811a468
>>> 0002
>>> [7.229929] 7980: 656c62617369645f 00038187 00ee
>>> 8007da837850
>>> [7.229932] 79a0: 09db50c0 09db569d 0006
>>> 89db568f
>>> [7.229936] [] lockdep_trace_alloc+0xe0/0xf0
>>> [7.229940] [] __kmalloc_track_caller+0x50/0x250
>>> [7.229945] [] devres_alloc_node+0x28/0x60
>>> [7.229949] [] devm_request_threaded_irq+0x50/0xe0
>>> [7.229955] [] pcc_mbox_request_channel+0x110/0x170
>>> [7.229960] [] acpi_cppc_processor_probe+0x264/0x414
>>> [7.229963] [] __acpi_processor_start+0x28/0xa0
>>> [7.229966] [] acpi_processor_start+0x44/0x54
>>> [7.229970] [] driver_probe_device+0x1fc/0x2b0
>>> [7.229974] [] __driver_attach+0xb4/0xc0
>>> [7.229977] [] bus_for_each_dev+0x5c/0xa0
>>> [7.229980] [] driver_attach+0x20/0x30
>>> [7.229983] [] bus_add_driver+0x110/0x230
>>> [7.229987] [] driver_register+0x60/0x100
>>> [7.229991] [] acpi_processor_driver_init+0x2c/0xb0
>>> [7.229996] [] do_one_initcall+0x38/0x130
>>> [7.23] [] kernel_init_freeable+0x210/0x2b4
>>> [7.230004] [] kernel_init+0x10/0x110
>>> [7.230007] [] ret_from_fork+0x10/0x50
>>>
>>> It's because the spinlock inside pcc_mbox_request_channel() is
>>> kept too long. This patch releases spinlock before request_irq()
>>> and free_irq() to fix this issue as spinlock is only needed to
>>> protect the channel data.
>>>
>>> Signed-off-by: Hoan Tran
>>> ---
>>> v3
>>> * Free mailbox irq before reset the channel data
>>> * Free channel if it fails to request the mailbox irq
>>>
>>> v2
>>> * Release spinlock before request_irq() and free_irq() instead of
>>> using mutex
>>>
>>>
>>> drivers/mailbox/pcc.c | 70
>>> +--
>>> 1 file changed, 35 insertions(+), 35 deletions(-)
>>>
>>> diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
>>> index 08c87fa..4b2f061 100644
>>> --- a/drivers/mailbox/pcc.c
>>> +++ b/drivers/mailbox/pcc.c
>>> @@ -224,6 +224,38 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
>>> }
>>>
>>> /**
>>> + * pcc_mbox_free_channel - Clients call this to free their Channel.
>>> + *
>>> + * @chan: Pointer to the mailbox channel as returned by
>>> + * pcc_mbox_request_channel()
>>> + */
>>> +void pcc_mbox_free_channel(struct mbox_chan *chan)
>>> +{
>>> + u32 id = chan - pcc_mbox_channels;
>>> + unsigned long flags;
>>> +
>>> + if (!chan || !chan->cl)
>>> + return;
>>> +
>>> + if (id >= pcc_mbox_ctrl.num_chans) {
>>> + pr_debug("pcc_mbox_free_channel: Invalid mbox_chan
>>> passed\n");
>>> + return;
>>> + }
>>> +
>>> + if (pcc_doorbell_irq[id] > 0)
>>> + devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan);
>>> +
>>> + spin_lock_irqsave(&chan->lock, flags);
>>> + chan->cl = NULL;
>>> + chan->active_req = NULL;
>>> + if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK))
>>> + chan->txdone_method = TXDONE_BY_POLL;
>>> +
>>> + spin_unlock_irqrestore(&chan->lock, flags);
>>> +}
>>> +EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
>>> +
>>> +/**
>>> * pcc_mbox_request_channel - PCC clients call this function to
>>> * request a pointer to their PCC subspace, from which they
>>> * can get the details of communicating with the remote.
>>> @@ -267,6 +299,8 @@ struct mbox
Re: [PATCH v3] mailbox: PCC: Fix lockdep warning when request PCC channel
HI Hoan,
On 11/9/2016 11:39 PM, Hoan Tran wrote:
> Hi All,
>
> On Thu, Oct 27, 2016 at 3:34 PM, Hoan Tran wrote:
>> This patch fixes the lockdep warning below
>>
>> [7.229767] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
>> [7.229776] [ cut here ]
>> [7.229787] WARNING: CPU: 1 PID: 1 at
>> linux-next/kernel/locking/lockdep.c:2876 loc
>> kdep_trace_alloc+0xe0/0xf0
>> [7.229790] Modules linked in:
>> [7.229793]
>> [7.229798] CPU: 1 PID: 1 Comm: swapper/0 Not tainted
>> 4.8.0-11756-g86c5152 #46
>> ...
>> [7.229900] Call trace:
>> [7.229903] Exception stack(0x8007da837890 to 0x8007da8379c0)
>> [7.229906] 7880: 8007da834000
>> 0001
>> [7.229909] 78a0: 8007da837a70 08a0 60c5
>> 003d
>> [7.229912] 78c0: 9374bc6a7f3c7832 00381878 09db7ab8
>> 002f
>> [7.229915] 78e0: 0811aabc 08be2548 8007da837990
>> 0811adf8
>> [7.229918] 7900: 8007da834000 024080c0 00c0
>> 09021000
>> [7.229921] 7920: 08c8f7c8
>> 8007da579810
>> [7.229923] 7940: 002f 8007da858000
>> 0001
>> [7.229926] 7960: 0001 0811a468
>> 0002
>> [7.229929] 7980: 656c62617369645f 00038187 00ee
>> 8007da837850
>> [7.229932] 79a0: 09db50c0 09db569d 0006
>> 89db568f
>> [7.229936] [] lockdep_trace_alloc+0xe0/0xf0
>> [7.229940] [] __kmalloc_track_caller+0x50/0x250
>> [7.229945] [] devres_alloc_node+0x28/0x60
>> [7.229949] [] devm_request_threaded_irq+0x50/0xe0
>> [7.229955] [] pcc_mbox_request_channel+0x110/0x170
>> [7.229960] [] acpi_cppc_processor_probe+0x264/0x414
>> [7.229963] [] __acpi_processor_start+0x28/0xa0
>> [7.229966] [] acpi_processor_start+0x44/0x54
>> [7.229970] [] driver_probe_device+0x1fc/0x2b0
>> [7.229974] [] __driver_attach+0xb4/0xc0
>> [7.229977] [] bus_for_each_dev+0x5c/0xa0
>> [7.229980] [] driver_attach+0x20/0x30
>> [7.229983] [] bus_add_driver+0x110/0x230
>> [7.229987] [] driver_register+0x60/0x100
>> [7.229991] [] acpi_processor_driver_init+0x2c/0xb0
>> [7.229996] [] do_one_initcall+0x38/0x130
>> [7.23] [] kernel_init_freeable+0x210/0x2b4
>> [7.230004] [] kernel_init+0x10/0x110
>> [7.230007] [] ret_from_fork+0x10/0x50
>>
>> It's because the spinlock inside pcc_mbox_request_channel() is
>> kept too long. This patch releases spinlock before request_irq()
>> and free_irq() to fix this issue as spinlock is only needed to
>> protect the channel data.
>>
>> Signed-off-by: Hoan Tran
>> ---
>> v3
>> * Free mailbox irq before reset the channel data
>> * Free channel if it fails to request the mailbox irq
>>
>> v2
>> * Release spinlock before request_irq() and free_irq() instead of
>> using mutex
>>
>>
>> drivers/mailbox/pcc.c | 70
>> +--
>> 1 file changed, 35 insertions(+), 35 deletions(-)
>>
>> diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
>> index 08c87fa..4b2f061 100644
>> --- a/drivers/mailbox/pcc.c
>> +++ b/drivers/mailbox/pcc.c
>> @@ -224,6 +224,38 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
>> }
>>
>> /**
>> + * pcc_mbox_free_channel - Clients call this to free their Channel.
>> + *
>> + * @chan: Pointer to the mailbox channel as returned by
>> + * pcc_mbox_request_channel()
>> + */
>> +void pcc_mbox_free_channel(struct mbox_chan *chan)
>> +{
>> + u32 id = chan - pcc_mbox_channels;
>> + unsigned long flags;
>> +
>> + if (!chan || !chan->cl)
>> + return;
>> +
>> + if (id >= pcc_mbox_ctrl.num_chans) {
>> + pr_debug("pcc_mbox_free_channel: Invalid mbox_chan
>> passed\n");
>> + return;
>> + }
>> +
>> + if (pcc_doorbell_irq[id] > 0)
>> + devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan);
>> +
>> + spin_lock_irqsave(&chan->lock, flags);
>> + chan->cl = NULL;
>> + chan->active_req = NULL;
>> + if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK))
>> + chan->txdone_method = TXDONE_BY_POLL;
>> +
>> + spin_unlock_irqrestore(&chan->lock, flags);
>> +}
>> +EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
>> +
>> +/**
>> * pcc_mbox_request_channel - PCC clients call this function to
>> * request a pointer to their PCC subspace, from which they
>> * can get the details of communicating with the remote.
>> @@ -267,6 +299,8 @@ struct mbox_chan *pcc_mbox_request_channel(struct
>> mbox_client *cl,
>> if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
>> chan->txdone_method |= TXDONE_BY_ACK;
>>
Re: [PATCH v3] mailbox: PCC: Fix lockdep warning when request PCC channel
Hi All,
On Thu, Oct 27, 2016 at 3:34 PM, Hoan Tran wrote:
> This patch fixes the lockdep warning below
>
> [7.229767] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
> [7.229776] [ cut here ]
> [7.229787] WARNING: CPU: 1 PID: 1 at
> linux-next/kernel/locking/lockdep.c:2876 loc
> kdep_trace_alloc+0xe0/0xf0
> [7.229790] Modules linked in:
> [7.229793]
> [7.229798] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.8.0-11756-g86c5152
> #46
> ...
> [7.229900] Call trace:
> [7.229903] Exception stack(0x8007da837890 to 0x8007da8379c0)
> [7.229906] 7880: 8007da834000
> 0001
> [7.229909] 78a0: 8007da837a70 08a0 60c5
> 003d
> [7.229912] 78c0: 9374bc6a7f3c7832 00381878 09db7ab8
> 002f
> [7.229915] 78e0: 0811aabc 08be2548 8007da837990
> 0811adf8
> [7.229918] 7900: 8007da834000 024080c0 00c0
> 09021000
> [7.229921] 7920: 08c8f7c8
> 8007da579810
> [7.229923] 7940: 002f 8007da858000
> 0001
> [7.229926] 7960: 0001 0811a468
> 0002
> [7.229929] 7980: 656c62617369645f 00038187 00ee
> 8007da837850
> [7.229932] 79a0: 09db50c0 09db569d 0006
> 89db568f
> [7.229936] [] lockdep_trace_alloc+0xe0/0xf0
> [7.229940] [] __kmalloc_track_caller+0x50/0x250
> [7.229945] [] devres_alloc_node+0x28/0x60
> [7.229949] [] devm_request_threaded_irq+0x50/0xe0
> [7.229955] [] pcc_mbox_request_channel+0x110/0x170
> [7.229960] [] acpi_cppc_processor_probe+0x264/0x414
> [7.229963] [] __acpi_processor_start+0x28/0xa0
> [7.229966] [] acpi_processor_start+0x44/0x54
> [7.229970] [] driver_probe_device+0x1fc/0x2b0
> [7.229974] [] __driver_attach+0xb4/0xc0
> [7.229977] [] bus_for_each_dev+0x5c/0xa0
> [7.229980] [] driver_attach+0x20/0x30
> [7.229983] [] bus_add_driver+0x110/0x230
> [7.229987] [] driver_register+0x60/0x100
> [7.229991] [] acpi_processor_driver_init+0x2c/0xb0
> [7.229996] [] do_one_initcall+0x38/0x130
> [7.23] [] kernel_init_freeable+0x210/0x2b4
> [7.230004] [] kernel_init+0x10/0x110
> [7.230007] [] ret_from_fork+0x10/0x50
>
> It's because the spinlock inside pcc_mbox_request_channel() is
> kept too long. This patch releases spinlock before request_irq()
> and free_irq() to fix this issue as spinlock is only needed to
> protect the channel data.
>
> Signed-off-by: Hoan Tran
> ---
> v3
> * Free mailbox irq before reset the channel data
> * Free channel if it fails to request the mailbox irq
>
> v2
> * Release spinlock before request_irq() and free_irq() instead of
> using mutex
>
>
> drivers/mailbox/pcc.c | 70
> +--
> 1 file changed, 35 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
> index 08c87fa..4b2f061 100644
> --- a/drivers/mailbox/pcc.c
> +++ b/drivers/mailbox/pcc.c
> @@ -224,6 +224,38 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
> }
>
> /**
> + * pcc_mbox_free_channel - Clients call this to free their Channel.
> + *
> + * @chan: Pointer to the mailbox channel as returned by
> + * pcc_mbox_request_channel()
> + */
> +void pcc_mbox_free_channel(struct mbox_chan *chan)
> +{
> + u32 id = chan - pcc_mbox_channels;
> + unsigned long flags;
> +
> + if (!chan || !chan->cl)
> + return;
> +
> + if (id >= pcc_mbox_ctrl.num_chans) {
> + pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n");
> + return;
> + }
> +
> + if (pcc_doorbell_irq[id] > 0)
> + devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan);
> +
> + spin_lock_irqsave(&chan->lock, flags);
> + chan->cl = NULL;
> + chan->active_req = NULL;
> + if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK))
> + chan->txdone_method = TXDONE_BY_POLL;
> +
> + spin_unlock_irqrestore(&chan->lock, flags);
> +}
> +EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
> +
> +/**
> * pcc_mbox_request_channel - PCC clients call this function to
> * request a pointer to their PCC subspace, from which they
> * can get the details of communicating with the remote.
> @@ -267,6 +299,8 @@ struct mbox_chan *pcc_mbox_request_channel(struct
> mbox_client *cl,
> if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
> chan->txdone_method |= TXDONE_BY_ACK;
>
> + spin_unlock_irqrestore(&chan->lock, flags);
> +
> if (pcc_doorbell_irq[subspace_id] > 0) {
> int rc;
>
> @@ -275,50 +309,16 @@ struct mbox_chan *p
[PATCH v3] mailbox: PCC: Fix lockdep warning when request PCC channel
This patch fixes the lockdep warning below
[7.229767] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
[7.229776] [ cut here ]
[7.229787] WARNING: CPU: 1 PID: 1 at
linux-next/kernel/locking/lockdep.c:2876 loc
kdep_trace_alloc+0xe0/0xf0
[7.229790] Modules linked in:
[7.229793]
[7.229798] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.8.0-11756-g86c5152
#46
...
[7.229900] Call trace:
[7.229903] Exception stack(0x8007da837890 to 0x8007da8379c0)
[7.229906] 7880: 8007da834000
0001
[7.229909] 78a0: 8007da837a70 08a0 60c5
003d
[7.229912] 78c0: 9374bc6a7f3c7832 00381878 09db7ab8
002f
[7.229915] 78e0: 0811aabc 08be2548 8007da837990
0811adf8
[7.229918] 7900: 8007da834000 024080c0 00c0
09021000
[7.229921] 7920: 08c8f7c8
8007da579810
[7.229923] 7940: 002f 8007da858000
0001
[7.229926] 7960: 0001 0811a468
0002
[7.229929] 7980: 656c62617369645f 00038187 00ee
8007da837850
[7.229932] 79a0: 09db50c0 09db569d 0006
89db568f
[7.229936] [] lockdep_trace_alloc+0xe0/0xf0
[7.229940] [] __kmalloc_track_caller+0x50/0x250
[7.229945] [] devres_alloc_node+0x28/0x60
[7.229949] [] devm_request_threaded_irq+0x50/0xe0
[7.229955] [] pcc_mbox_request_channel+0x110/0x170
[7.229960] [] acpi_cppc_processor_probe+0x264/0x414
[7.229963] [] __acpi_processor_start+0x28/0xa0
[7.229966] [] acpi_processor_start+0x44/0x54
[7.229970] [] driver_probe_device+0x1fc/0x2b0
[7.229974] [] __driver_attach+0xb4/0xc0
[7.229977] [] bus_for_each_dev+0x5c/0xa0
[7.229980] [] driver_attach+0x20/0x30
[7.229983] [] bus_add_driver+0x110/0x230
[7.229987] [] driver_register+0x60/0x100
[7.229991] [] acpi_processor_driver_init+0x2c/0xb0
[7.229996] [] do_one_initcall+0x38/0x130
[7.23] [] kernel_init_freeable+0x210/0x2b4
[7.230004] [] kernel_init+0x10/0x110
[7.230007] [] ret_from_fork+0x10/0x50
It's because the spinlock inside pcc_mbox_request_channel() is
kept too long. This patch releases spinlock before request_irq()
and free_irq() to fix this issue as spinlock is only needed to
protect the channel data.
Signed-off-by: Hoan Tran
---
v3
* Free mailbox irq before reset the channel data
* Free channel if it fails to request the mailbox irq
v2
* Release spinlock before request_irq() and free_irq() instead of
using mutex
drivers/mailbox/pcc.c | 70 +--
1 file changed, 35 insertions(+), 35 deletions(-)
diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index 08c87fa..4b2f061 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c
@@ -224,6 +224,38 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
}
/**
+ * pcc_mbox_free_channel - Clients call this to free their Channel.
+ *
+ * @chan: Pointer to the mailbox channel as returned by
+ * pcc_mbox_request_channel()
+ */
+void pcc_mbox_free_channel(struct mbox_chan *chan)
+{
+ u32 id = chan - pcc_mbox_channels;
+ unsigned long flags;
+
+ if (!chan || !chan->cl)
+ return;
+
+ if (id >= pcc_mbox_ctrl.num_chans) {
+ pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n");
+ return;
+ }
+
+ if (pcc_doorbell_irq[id] > 0)
+ devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan);
+
+ spin_lock_irqsave(&chan->lock, flags);
+ chan->cl = NULL;
+ chan->active_req = NULL;
+ if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK))
+ chan->txdone_method = TXDONE_BY_POLL;
+
+ spin_unlock_irqrestore(&chan->lock, flags);
+}
+EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
+
+/**
* pcc_mbox_request_channel - PCC clients call this function to
* request a pointer to their PCC subspace, from which they
* can get the details of communicating with the remote.
@@ -267,6 +299,8 @@ struct mbox_chan *pcc_mbox_request_channel(struct
mbox_client *cl,
if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
chan->txdone_method |= TXDONE_BY_ACK;
+ spin_unlock_irqrestore(&chan->lock, flags);
+
if (pcc_doorbell_irq[subspace_id] > 0) {
int rc;
@@ -275,50 +309,16 @@ struct mbox_chan *pcc_mbox_request_channel(struct
mbox_client *cl,
if (unlikely(rc)) {
dev_err(dev, "failed to register PCC interrupt %d\n",
pcc_doorbell_irq[subspace_id]);
+ pcc_mbox_free_channel(chan);
