* [PATCH] mmc: sdhci: fix possible scheduling while atomic
@ 2014-01-17 19:57 Andrew Bresticker
2014-01-17 22:58 ` Philip Rakity
0 siblings, 1 reply; 10+ messages in thread
From: Andrew Bresticker @ 2014-01-17 19:57 UTC (permalink / raw)
To: Chris Ball; +Cc: linux-mmc, linux-kernel, Andrew Bresticker
sdhci_execute_tuning() takes host->lock without disabling interrupts.
Use spin_lock_irq{save,restore} instead so that we avoid taking an
interrupt and scheduling while holding host->lock.
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
---
drivers/mmc/host/sdhci.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index ec3eb30..84c80e7 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1857,12 +1857,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
unsigned long timeout;
int err = 0;
bool requires_tuning_nonuhs = false;
+ unsigned long flags;
host = mmc_priv(mmc);
sdhci_runtime_pm_get(host);
disable_irq(host->irq);
- spin_lock(&host->lock);
+ spin_lock_irqsave(&host->lock, flags);
ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
@@ -1882,14 +1883,14 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
requires_tuning_nonuhs)
ctrl |= SDHCI_CTRL_EXEC_TUNING;
else {
- spin_unlock(&host->lock);
+ spin_unlock_irqrestore(&host->lock, flags);
enable_irq(host->irq);
sdhci_runtime_pm_put(host);
return 0;
}
if (host->ops->platform_execute_tuning) {
- spin_unlock(&host->lock);
+ spin_unlock_irqrestore(&host->lock, flags);
enable_irq(host->irq);
err = host->ops->platform_execute_tuning(host, opcode);
sdhci_runtime_pm_put(host);
@@ -1963,7 +1964,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
host->cmd = NULL;
host->mrq = NULL;
- spin_unlock(&host->lock);
+ spin_unlock_irqrestore(&host->lock, flags);
enable_irq(host->irq);
/* Wait for Buffer Read Ready interrupt */
@@ -1971,7 +1972,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
(host->tuning_done == 1),
msecs_to_jiffies(50));
disable_irq(host->irq);
- spin_lock(&host->lock);
+ spin_lock_irqsave(&host->lock, flags);
if (!host->tuning_done) {
pr_info(DRIVER_NAME ": Timeout waiting for "
@@ -2046,7 +2047,7 @@ out:
err = 0;
sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
- spin_unlock(&host->lock);
+ spin_unlock_irqrestore(&host->lock, flags);
enable_irq(host->irq);
sdhci_runtime_pm_put(host);
--
1.8.5.2
^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [PATCH] mmc: sdhci: fix possible scheduling while atomic
2014-01-17 19:57 [PATCH] mmc: sdhci: fix possible scheduling while atomic Andrew Bresticker
@ 2014-01-17 22:58 ` Philip Rakity
2014-01-17 23:10 ` Andrew Bresticker
2014-01-17 23:11 ` John Tobias
0 siblings, 2 replies; 10+ messages in thread
From: Philip Rakity @ 2014-01-17 22:58 UTC (permalink / raw)
To: Andrew Bresticker
Cc: Chris Ball, linux-mmc@vger.kernel.org,
linux-kernel@vger.kernel.org
On Jan 17, 2014, at 7:57 PM, Andrew Bresticker <abrestic@chromium.org> wrote:
> sdhci_execute_tuning() takes host->lock without disabling interrupts.
> Use spin_lock_irq{save,restore} instead so that we avoid taking an
> interrupt and scheduling while holding host->lock.
>
> Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
> ---
> drivers/mmc/host/sdhci.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index ec3eb30..84c80e7 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1857,12 +1857,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> unsigned long timeout;
> int err = 0;
> bool requires_tuning_nonuhs = false;
> + unsigned long flags;
>
> host = mmc_priv(mmc);
>
> sdhci_runtime_pm_get(host);
> disable_irq(host->irq);
> - spin_lock(&host->lock);
> + spin_lock_irqsave(&host->lock, flags);
The disable_irq() call stops the controller from doing interrupts.
Please explain what problem you are seeing
>
> ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>
> @@ -1882,14 +1883,14 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> requires_tuning_nonuhs)
> ctrl |= SDHCI_CTRL_EXEC_TUNING;
> else {
> - spin_unlock(&host->lock);
> + spin_unlock_irqrestore(&host->lock, flags);
> enable_irq(host->irq);
> sdhci_runtime_pm_put(host);
> return 0;
> }
>
> if (host->ops->platform_execute_tuning) {
> - spin_unlock(&host->lock);
> + spin_unlock_irqrestore(&host->lock, flags);
> enable_irq(host->irq);
> err = host->ops->platform_execute_tuning(host, opcode);
> sdhci_runtime_pm_put(host);
> @@ -1963,7 +1964,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> host->cmd = NULL;
> host->mrq = NULL;
>
> - spin_unlock(&host->lock);
> + spin_unlock_irqrestore(&host->lock, flags);
> enable_irq(host->irq);
>
> /* Wait for Buffer Read Ready interrupt */
> @@ -1971,7 +1972,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> (host->tuning_done == 1),
> msecs_to_jiffies(50));
> disable_irq(host->irq);
> - spin_lock(&host->lock);
> + spin_lock_irqsave(&host->lock, flags);
>
> if (!host->tuning_done) {
> pr_info(DRIVER_NAME ": Timeout waiting for "
> @@ -2046,7 +2047,7 @@ out:
> err = 0;
>
> sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
> - spin_unlock(&host->lock);
> + spin_unlock_irqrestore(&host->lock, flags);
> enable_irq(host->irq);
> sdhci_runtime_pm_put(host);
>
> --
> 1.8.5.2
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] mmc: sdhci: fix possible scheduling while atomic
2014-01-17 22:58 ` Philip Rakity
@ 2014-01-17 23:10 ` Andrew Bresticker
2014-01-17 23:11 ` John Tobias
1 sibling, 0 replies; 10+ messages in thread
From: Andrew Bresticker @ 2014-01-17 23:10 UTC (permalink / raw)
To: Philip Rakity
Cc: Chris Ball, linux-mmc@vger.kernel.org,
linux-kernel@vger.kernel.org
On Fri, Jan 17, 2014 at 2:58 PM, Philip Rakity <prakity@nvidia.com> wrote:
>
> On Jan 17, 2014, at 7:57 PM, Andrew Bresticker <abrestic@chromium.org> wrote:
>
>> sdhci_execute_tuning() takes host->lock without disabling interrupts.
>> Use spin_lock_irq{save,restore} instead so that we avoid taking an
>> interrupt and scheduling while holding host->lock.
>>
>> Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
>> ---
>> drivers/mmc/host/sdhci.c | 13 +++++++------
>> 1 file changed, 7 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index ec3eb30..84c80e7 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -1857,12 +1857,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> unsigned long timeout;
>> int err = 0;
>> bool requires_tuning_nonuhs = false;
>> + unsigned long flags;
>>
>> host = mmc_priv(mmc);
>>
>> sdhci_runtime_pm_get(host);
>> disable_irq(host->irq);
>> - spin_lock(&host->lock);
>> + spin_lock_irqsave(&host->lock, flags);
>
>
> The disable_irq() call stops the controller from doing interrupts.
Right, but it does not disable other IRQ sources that could cause us
to schedule.
> Please explain what problem you are seeing
The issue we were seeing was that a card-detect interrupt was
triggered (*not* the controller interrupt), causing the card-detect
irq thread to recurse on host->lock:
[ 60.962218] BUG: spinlock cpu recursion on CPU#0, irq/362-700b040/89
[ 60.975253] lock: 0xee210c80, .magic: dead4ead, .owner:
kworker/u8:1/33, .owner_cpu: 0
[ 60.991638] CPU: 0 PID: 89 Comm: irq/362-700b040 Not tainted 3.10.18 #2
[ 61.005199] [<800153cc>] (unwind_backtrace+0x0/0x118) from
[<800124e4>] (show_stack+0x20/0x24)
[ 61.022824] [<800124e4>] (show_stack+0x20/0x24) from [<8053d584>]
(dump_stack+0x20/0x28)
[ 61.039389] [<8053d584>] (dump_stack+0x20/0x28) from [<8021d508>]
(spin_dump+0x80/0x94)
[ 61.055773] [<8021d508>] (spin_dump+0x80/0x94) from [<8021d548>]
(spin_bug+0x2c/0x30)
[ 61.071803] [<8021d548>] (spin_bug+0x2c/0x30) from [<8021d61c>]
(do_raw_spin_lock+0x70/0x15c)
[ 61.089250] [<8021d61c>] (do_raw_spin_lock+0x70/0x15c) from
[<8054098c>] (_raw_spin_lock_irqsave+0x20/0x28)
[ 61.109175] [<8054098c>] (_raw_spin_lock_irqsave+0x20/0x28) from
[<803e2af0>] (sdhci_card_event+0x28/0xfc)
[ 61.128922] [<803e2af0>] (sdhci_card_event+0x28/0xfc) from
[<803dc880>] (mmc_gpio_cd_irqt+0x30/0x4c)
[ 61.147609] [<803dc880>] (mmc_gpio_cd_irqt+0x30/0x4c) from
[<80091858>] (irq_thread+0xf0/0x224)
[ 61.165412] [<80091858>] (irq_thread+0xf0/0x224) from [<80050db4>]
(kthread+0xc8/0xd8)
[ 61.181623] [<80050db4>] (kthread+0xc8/0xd8) from [<8000e4d8>]
(ret_from_fork+0x14/0x20)
Thanks,
Andrew
>
>>
>> ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>>
>> @@ -1882,14 +1883,14 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> requires_tuning_nonuhs)
>> ctrl |= SDHCI_CTRL_EXEC_TUNING;
>> else {
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>> sdhci_runtime_pm_put(host);
>> return 0;
>> }
>>
>> if (host->ops->platform_execute_tuning) {
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>> err = host->ops->platform_execute_tuning(host, opcode);
>> sdhci_runtime_pm_put(host);
>> @@ -1963,7 +1964,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> host->cmd = NULL;
>> host->mrq = NULL;
>>
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>>
>> /* Wait for Buffer Read Ready interrupt */
>> @@ -1971,7 +1972,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> (host->tuning_done == 1),
>> msecs_to_jiffies(50));
>> disable_irq(host->irq);
>> - spin_lock(&host->lock);
>> + spin_lock_irqsave(&host->lock, flags);
>>
>> if (!host->tuning_done) {
>> pr_info(DRIVER_NAME ": Timeout waiting for "
>> @@ -2046,7 +2047,7 @@ out:
>> err = 0;
>>
>> sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>> sdhci_runtime_pm_put(host);
>>
>> --
>> 1.8.5.2
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] mmc: sdhci: fix possible scheduling while atomic
2014-01-17 22:58 ` Philip Rakity
2014-01-17 23:10 ` Andrew Bresticker
@ 2014-01-17 23:11 ` John Tobias
2014-01-17 23:16 ` Andrew Bresticker
1 sibling, 1 reply; 10+ messages in thread
From: John Tobias @ 2014-01-17 23:11 UTC (permalink / raw)
To: Philip Rakity
Cc: Andrew Bresticker, Chris Ball, linux-mmc@vger.kernel.org,
linux-kernel@vger.kernel.org
There's an existing patch for that...
http://www.spinics.net/lists/arm-kernel/msg296596.html
On Fri, Jan 17, 2014 at 2:58 PM, Philip Rakity <prakity@nvidia.com> wrote:
>
> On Jan 17, 2014, at 7:57 PM, Andrew Bresticker <abrestic@chromium.org> wrote:
>
>> sdhci_execute_tuning() takes host->lock without disabling interrupts.
>> Use spin_lock_irq{save,restore} instead so that we avoid taking an
>> interrupt and scheduling while holding host->lock.
>>
>> Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
>> ---
>> drivers/mmc/host/sdhci.c | 13 +++++++------
>> 1 file changed, 7 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index ec3eb30..84c80e7 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -1857,12 +1857,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> unsigned long timeout;
>> int err = 0;
>> bool requires_tuning_nonuhs = false;
>> + unsigned long flags;
>>
>> host = mmc_priv(mmc);
>>
>> sdhci_runtime_pm_get(host);
>> disable_irq(host->irq);
>> - spin_lock(&host->lock);
>> + spin_lock_irqsave(&host->lock, flags);
>
>
> The disable_irq() call stops the controller from doing interrupts.
> Please explain what problem you are seeing
>
>>
>> ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>>
>> @@ -1882,14 +1883,14 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> requires_tuning_nonuhs)
>> ctrl |= SDHCI_CTRL_EXEC_TUNING;
>> else {
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>> sdhci_runtime_pm_put(host);
>> return 0;
>> }
>>
>> if (host->ops->platform_execute_tuning) {
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>> err = host->ops->platform_execute_tuning(host, opcode);
>> sdhci_runtime_pm_put(host);
>> @@ -1963,7 +1964,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> host->cmd = NULL;
>> host->mrq = NULL;
>>
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>>
>> /* Wait for Buffer Read Ready interrupt */
>> @@ -1971,7 +1972,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> (host->tuning_done == 1),
>> msecs_to_jiffies(50));
>> disable_irq(host->irq);
>> - spin_lock(&host->lock);
>> + spin_lock_irqsave(&host->lock, flags);
>>
>> if (!host->tuning_done) {
>> pr_info(DRIVER_NAME ": Timeout waiting for "
>> @@ -2046,7 +2047,7 @@ out:
>> err = 0;
>>
>> sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>> sdhci_runtime_pm_put(host);
>>
>> --
>> 1.8.5.2
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] mmc: sdhci: fix possible scheduling while atomic
2014-01-17 23:11 ` John Tobias
@ 2014-01-17 23:16 ` Andrew Bresticker
2014-01-17 23:40 ` Chris Ball
0 siblings, 1 reply; 10+ messages in thread
From: Andrew Bresticker @ 2014-01-17 23:16 UTC (permalink / raw)
To: John Tobias
Cc: Philip Rakity, Chris Ball, linux-mmc@vger.kernel.org,
linux-kernel@vger.kernel.org
On Fri, Jan 17, 2014 at 3:11 PM, John Tobias <john.tobias.ph@gmail.com> wrote:
> There's an existing patch for that...
> http://www.spinics.net/lists/arm-kernel/msg296596.html
Ah, I see. Looks like it has yet to be picked up...
>
> On Fri, Jan 17, 2014 at 2:58 PM, Philip Rakity <prakity@nvidia.com> wrote:
>>
>> On Jan 17, 2014, at 7:57 PM, Andrew Bresticker <abrestic@chromium.org> wrote:
>>
>>> sdhci_execute_tuning() takes host->lock without disabling interrupts.
>>> Use spin_lock_irq{save,restore} instead so that we avoid taking an
>>> interrupt and scheduling while holding host->lock.
>>>
>>> Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
>>> ---
>>> drivers/mmc/host/sdhci.c | 13 +++++++------
>>> 1 file changed, 7 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>> index ec3eb30..84c80e7 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>> @@ -1857,12 +1857,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>> unsigned long timeout;
>>> int err = 0;
>>> bool requires_tuning_nonuhs = false;
>>> + unsigned long flags;
>>>
>>> host = mmc_priv(mmc);
>>>
>>> sdhci_runtime_pm_get(host);
>>> disable_irq(host->irq);
>>> - spin_lock(&host->lock);
>>> + spin_lock_irqsave(&host->lock, flags);
>>
>>
>> The disable_irq() call stops the controller from doing interrupts.
>> Please explain what problem you are seeing
>>
>>>
>>> ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>>>
>>> @@ -1882,14 +1883,14 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>> requires_tuning_nonuhs)
>>> ctrl |= SDHCI_CTRL_EXEC_TUNING;
>>> else {
>>> - spin_unlock(&host->lock);
>>> + spin_unlock_irqrestore(&host->lock, flags);
>>> enable_irq(host->irq);
>>> sdhci_runtime_pm_put(host);
>>> return 0;
>>> }
>>>
>>> if (host->ops->platform_execute_tuning) {
>>> - spin_unlock(&host->lock);
>>> + spin_unlock_irqrestore(&host->lock, flags);
>>> enable_irq(host->irq);
>>> err = host->ops->platform_execute_tuning(host, opcode);
>>> sdhci_runtime_pm_put(host);
>>> @@ -1963,7 +1964,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>> host->cmd = NULL;
>>> host->mrq = NULL;
>>>
>>> - spin_unlock(&host->lock);
>>> + spin_unlock_irqrestore(&host->lock, flags);
>>> enable_irq(host->irq);
>>>
>>> /* Wait for Buffer Read Ready interrupt */
>>> @@ -1971,7 +1972,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>> (host->tuning_done == 1),
>>> msecs_to_jiffies(50));
>>> disable_irq(host->irq);
>>> - spin_lock(&host->lock);
>>> + spin_lock_irqsave(&host->lock, flags);
>>>
>>> if (!host->tuning_done) {
>>> pr_info(DRIVER_NAME ": Timeout waiting for "
>>> @@ -2046,7 +2047,7 @@ out:
>>> err = 0;
>>>
>>> sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
>>> - spin_unlock(&host->lock);
>>> + spin_unlock_irqrestore(&host->lock, flags);
>>> enable_irq(host->irq);
>>> sdhci_runtime_pm_put(host);
>>>
>>> --
>>> 1.8.5.2
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at http://www.tux.org/lkml/
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] mmc: sdhci: fix possible scheduling while atomic
2014-01-17 23:16 ` Andrew Bresticker
@ 2014-01-17 23:40 ` Chris Ball
2014-01-18 3:21 ` Andrew Bresticker
0 siblings, 1 reply; 10+ messages in thread
From: Chris Ball @ 2014-01-17 23:40 UTC (permalink / raw)
To: Andrew Bresticker
Cc: John Tobias, Philip Rakity, linux-mmc@vger.kernel.org,
linux-kernel@vger.kernel.org, Dong Aisheng
Hi, adding Aisheng,
On Fri, Jan 17 2014, Andrew Bresticker wrote:
> On Fri, Jan 17, 2014 at 3:11 PM, John Tobias <john.tobias.ph@gmail.com> wrote:
>> There's an existing patch for that...
>> http://www.spinics.net/lists/arm-kernel/msg296596.html
>
> Ah, I see. Looks like it has yet to be picked up...
The patches aren't quite identical -- Andrew's leaves the
disable_irq() call in and Aisheng's removes it. Which should I take?
Thanks,
- Chris.
--
Chris Ball <chris@printf.net> <http://printf.net/>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] mmc: sdhci: fix possible scheduling while atomic
2014-01-17 23:40 ` Chris Ball
@ 2014-01-18 3:21 ` Andrew Bresticker
2014-01-18 3:40 ` Chris Ball
0 siblings, 1 reply; 10+ messages in thread
From: Andrew Bresticker @ 2014-01-18 3:21 UTC (permalink / raw)
To: Chris Ball
Cc: John Tobias, Philip Rakity, linux-mmc@vger.kernel.org,
linux-kernel@vger.kernel.org, Dong Aisheng
On Fri, Jan 17, 2014 at 3:40 PM, Chris Ball <chris@printf.net> wrote:
> Hi, adding Aisheng,
>
> On Fri, Jan 17 2014, Andrew Bresticker wrote:
>> On Fri, Jan 17, 2014 at 3:11 PM, John Tobias <john.tobias.ph@gmail.com> wrote:
>>> There's an existing patch for that...
>>> http://www.spinics.net/lists/arm-kernel/msg296596.html
>>
>> Ah, I see. Looks like it has yet to be picked up...
>
> The patches aren't quite identical -- Andrew's leaves the
> disable_irq() call in and Aisheng's removes it. Which should I take?
Since the disable_irq() is now redundant, I suppose Aisheng's is more correct.
Thanks,
Andrew
>
> Thanks,
>
> - Chris.
> --
> Chris Ball <chris@printf.net> <http://printf.net/>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] mmc: sdhci: fix possible scheduling while atomic
2014-01-18 3:21 ` Andrew Bresticker
@ 2014-01-18 3:40 ` Chris Ball
0 siblings, 0 replies; 10+ messages in thread
From: Chris Ball @ 2014-01-18 3:40 UTC (permalink / raw)
To: Andrew Bresticker
Cc: John Tobias, Philip Rakity, linux-mmc@vger.kernel.org,
linux-kernel@vger.kernel.org, Dong Aisheng
Hi,
On Sat, Jan 18 2014, Andrew Bresticker wrote:
>>>> There's an existing patch for that...
>>>> http://www.spinics.net/lists/arm-kernel/msg296596.html
>>>
>>> Ah, I see. Looks like it has yet to be picked up...
>>
>> The patches aren't quite identical -- Andrew's leaves the
>> disable_irq() call in and Aisheng's removes it. Which should I take?
>
> Since the disable_irq() is now redundant, I suppose Aisheng's is more correct
Thanks, pushed Aisheng's version to mmc-next for 3.14.
- Chris.
--
Chris Ball <chris@printf.net> <http://printf.net/>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] mmc: sdhci: fix possible scheduling while atomic
@ 2014-01-20 9:51 Philip Rakity
2014-01-20 15:03 ` Philip Rakity
0 siblings, 1 reply; 10+ messages in thread
From: Philip Rakity @ 2014-01-20 9:51 UTC (permalink / raw)
To: Chris Ball; +Cc: linux-mmc@vger.kernel.org
Chris,
The suggested fix can lock out interrupts for up to 150ms. There needs to be another way.
So, I would strongly recommend we find another solution.
Philip
On Jan 17, 2014, at 7:57 PM, Andrew Bresticker <abrestic@chromium.org> wrote:
> sdhci_execute_tuning() takes host->lock without disabling interrupts.
> Use spin_lock_irq{save,restore} instead so that we avoid taking an
> interrupt and scheduling while holding host->lock.
>
> Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
> ---
> drivers/mmc/host/sdhci.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index ec3eb30..84c80e7 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1857,12 +1857,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> unsigned long timeout;
> int err = 0;
> bool requires_tuning_nonuhs = false;
> + unsigned long flags;
>
> host = mmc_priv(mmc);
>
> sdhci_runtime_pm_get(host);
> disable_irq(host->irq);
> - spin_lock(&host->lock);
> + spin_lock_irqsave(&host->lock, flags);
The disable_irq() call stops the controller from doing interrupts.
Please explain what problem you are seeing
>
> ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>
> @@ -1882,14 +1883,14 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> requires_tuning_nonuhs)
> ctrl |= SDHCI_CTRL_EXEC_TUNING;
> else {
> - spin_unlock(&host->lock);
> + spin_unlock_irqrestore(&host->lock, flags);
> enable_irq(host->irq);
> sdhci_runtime_pm_put(host);
> return 0;
> }
>
> if (host->ops->platform_execute_tuning) {
> - spin_unlock(&host->lock);
> + spin_unlock_irqrestore(&host->lock, flags);
> enable_irq(host->irq);
> err = host->ops->platform_execute_tuning(host, opcode);
> sdhci_runtime_pm_put(host);
> @@ -1963,7 +1964,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> host->cmd = NULL;
> host->mrq = NULL;
>
> - spin_unlock(&host->lock);
> + spin_unlock_irqrestore(&host->lock, flags);
> enable_irq(host->irq);
>
> /* Wait for Buffer Read Ready interrupt */
> @@ -1971,7 +1972,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> (host->tuning_done == 1),
> msecs_to_jiffies(50));
> disable_irq(host->irq);
> - spin_lock(&host->lock);
> + spin_lock_irqsave(&host->lock, flags);
>
> if (!host->tuning_done) {
> pr_info(DRIVER_NAME ": Timeout waiting for "
> @@ -2046,7 +2047,7 @@ out:
> err = 0;
>
> sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
> - spin_unlock(&host->lock);
> + spin_unlock_irqrestore(&host->lock, flags);
> enable_irq(host->irq);
> sdhci_runtime_pm_put(host);
>
> --
> 1.8.5.2
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
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^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] mmc: sdhci: fix possible scheduling while atomic
2014-01-20 9:51 Philip Rakity
@ 2014-01-20 15:03 ` Philip Rakity
0 siblings, 0 replies; 10+ messages in thread
From: Philip Rakity @ 2014-01-20 15:03 UTC (permalink / raw)
To: Chris Ball; +Cc: linux-mmc@vger.kernel.org
I have no way to test this problem but I was thinking along the lines of
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1862,6 +1862,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32
sdhci_runtime_pm_get(host);
disable_irq(host->irq);
+ sdhci_disable_card_detection(host);
spin_lock(&host->lock);
ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
@@ -1883,6 +1884,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32
ctrl |= SDHCI_CTRL_EXEC_TUNING;
else {
spin_unlock(&host->lock);
+ sdhci_enable_card_detection(host);
enable_irq(host->irq);
sdhci_runtime_pm_put(host);
return 0;
@@ -1890,6 +1892,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32
if (host->ops->platform_execute_tuning) {
spin_unlock(&host->lock);
+ sdhci_enable_card_detection(host);
enable_irq(host->irq);
err = host->ops->platform_execute_tuning(host, opcode);
sdhci_runtime_pm_put(host);
@@ -2047,6 +2050,7 @@ out:
sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
spin_unlock(&host->lock);
+ sdhci_enable_card_detection(host);
enable_irq(host->irq);
sdhci_runtime_pm_put(host);
regards,
Philip
On Jan 20, 2014, at 9:51 AM, Philip Rakity <prakity@nvidia.com> wrote:
>
> Chris,
>
> The suggested fix can lock out interrupts for up to 150ms. There needs to be another way.
> So, I would strongly recommend we find another solution.
>
> Philip
>
> On Jan 17, 2014, at 7:57 PM, Andrew Bresticker <abrestic@chromium.org> wrote:
>
>> sdhci_execute_tuning() takes host->lock without disabling interrupts.
>> Use spin_lock_irq{save,restore} instead so that we avoid taking an
>> interrupt and scheduling while holding host->lock.
>>
>> Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
>> ---
>> drivers/mmc/host/sdhci.c | 13 +++++++------
>> 1 file changed, 7 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index ec3eb30..84c80e7 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -1857,12 +1857,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> unsigned long timeout;
>> int err = 0;
>> bool requires_tuning_nonuhs = false;
>> + unsigned long flags;
>>
>> host = mmc_priv(mmc);
>>
>> sdhci_runtime_pm_get(host);
>> disable_irq(host->irq);
>> - spin_lock(&host->lock);
>> + spin_lock_irqsave(&host->lock, flags);
>
>
> The disable_irq() call stops the controller from doing interrupts.
> Please explain what problem you are seeing
>
>>
>> ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>>
>> @@ -1882,14 +1883,14 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> requires_tuning_nonuhs)
>> ctrl |= SDHCI_CTRL_EXEC_TUNING;
>> else {
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>> sdhci_runtime_pm_put(host);
>> return 0;
>> }
>>
>> if (host->ops->platform_execute_tuning) {
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>> err = host->ops->platform_execute_tuning(host, opcode);
>> sdhci_runtime_pm_put(host);
>> @@ -1963,7 +1964,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> host->cmd = NULL;
>> host->mrq = NULL;
>>
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>>
>> /* Wait for Buffer Read Ready interrupt */
>> @@ -1971,7 +1972,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> (host->tuning_done == 1),
>> msecs_to_jiffies(50));
>> disable_irq(host->irq);
>> - spin_lock(&host->lock);
>> + spin_lock_irqsave(&host->lock, flags);
>>
>> if (!host->tuning_done) {
>> pr_info(DRIVER_NAME ": Timeout waiting for "
>> @@ -2046,7 +2047,7 @@ out:
>> err = 0;
>>
>> sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
>> - spin_unlock(&host->lock);
>> + spin_unlock_irqrestore(&host->lock, flags);
>> enable_irq(host->irq);
>> sdhci_runtime_pm_put(host);
>>
>> --
>> 1.8.5.2
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
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is prohibited. If you are not the intended recipient, please contact the sender by
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-----------------------------------------------------------------------------------
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2014-01-20 15:03 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
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2014-01-17 19:57 [PATCH] mmc: sdhci: fix possible scheduling while atomic Andrew Bresticker
2014-01-17 22:58 ` Philip Rakity
2014-01-17 23:10 ` Andrew Bresticker
2014-01-17 23:11 ` John Tobias
2014-01-17 23:16 ` Andrew Bresticker
2014-01-17 23:40 ` Chris Ball
2014-01-18 3:21 ` Andrew Bresticker
2014-01-18 3:40 ` Chris Ball
-- strict thread matches above, loose matches on Subject: below --
2014-01-20 9:51 Philip Rakity
2014-01-20 15:03 ` Philip Rakity
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