[PATCH] ata: libata-core: Do not call ata_dev_power_set_standby() twice

[PATCH] ata: libata-core: Do not call ata_dev_power_set_standby() twice

[Niklas Cassel]

From: Damien Le Moal <dlemoal@kernel.org>

For regular system shutdown, ata_dev_power_set_standby() will be
executed twice: once the scsi device is removed and another when
ata_pci_shutdown_one() executes and EH completes unloading the devices.

Make the second call to ata_dev_power_set_standby() do nothing by using
ata_dev_power_is_active() and return if the device is already in
standby.

Fixes: 2da4c5e24e86 ("ata: libata-core: Improve ata_dev_power_set_active()")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
This fix was originally part of patch that contained both a fix and
a revert in a single patch:
https://lore.kernel.org/linux-ide/20240111115123.1258422-3-dlemoal@kernel.org/

This patch contains the only the fix (as it is valid even without the
revert), without the revert.

Updated the Fixes tag to point to a more appropriate commit, since we
no longer revert any code.

 drivers/ata/libata-core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index d9f80f4f70f5..af2334bc806d 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -85,6 +85,7 @@ static unsigned int ata_dev_init_params(struct ata_device *dev,
 static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
 static void ata_dev_xfermask(struct ata_device *dev);
 static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
+static bool ata_dev_power_is_active(struct ata_device *dev);
 
 atomic_t ata_print_id = ATOMIC_INIT(0);
 
@@ -2017,8 +2018,9 @@ void ata_dev_power_set_standby(struct ata_device *dev)
 	struct ata_taskfile tf;
 	unsigned int err_mask;
 
-	/* If the device is already sleeping, do nothing. */
-	if (dev->flags & ATA_DFLAG_SLEEPING)
+	/* If the device is already sleeping or in standby, do nothing. */
+	if ((dev->flags & ATA_DFLAG_SLEEPING) ||
+	    !ata_dev_power_is_active(dev))
 		return;
 
 	/*
-- 
2.43.1

Re: [PATCH] ata: libata-core: Do not call ata_dev_power_set_standby() twice

[Damien Le Moal]

On 2/16/24 20:20, Niklas Cassel wrote:
> From: Damien Le Moal <dlemoal@kernel.org>
> 
> For regular system shutdown, ata_dev_power_set_standby() will be
> executed twice: once the scsi device is removed and another when
> ata_pci_shutdown_one() executes and EH completes unloading the devices.
> 
> Make the second call to ata_dev_power_set_standby() do nothing by using
> ata_dev_power_is_active() and return if the device is already in
> standby.
> 
> Fixes: 2da4c5e24e86 ("ata: libata-core: Improve ata_dev_power_set_active()")
> Cc: stable@vger.kernel.org
> Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
> Signed-off-by: Niklas Cassel <cassel@kernel.org>
> ---
> This fix was originally part of patch that contained both a fix and
> a revert in a single patch:
> https://lore.kernel.org/linux-ide/20240111115123.1258422-3-dlemoal@kernel.org/
> 
> This patch contains the only the fix (as it is valid even without the
> revert), without the revert.
> 
> Updated the Fixes tag to point to a more appropriate commit, since we
> no longer revert any code.
> 
>  drivers/ata/libata-core.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index d9f80f4f70f5..af2334bc806d 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -85,6 +85,7 @@ static unsigned int ata_dev_init_params(struct ata_device *dev,
>  static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
>  static void ata_dev_xfermask(struct ata_device *dev);
>  static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
> +static bool ata_dev_power_is_active(struct ata_device *dev);

I forgot what I did originally but didn't I move the code of
ata_dev_power_is_active() before ata_dev_power_set_standby() to avoid this
forward declaration ?

With that, the code is a little odd as ata_dev_power_is_active() is defined
between ata_dev_power_set_standby() and ata_dev_power_set_active() but both
functions use it...

>  
>  atomic_t ata_print_id = ATOMIC_INIT(0);
>  
> @@ -2017,8 +2018,9 @@ void ata_dev_power_set_standby(struct ata_device *dev)
>  	struct ata_taskfile tf;
>  	unsigned int err_mask;
>  
> -	/* If the device is already sleeping, do nothing. */
> -	if (dev->flags & ATA_DFLAG_SLEEPING)
> +	/* If the device is already sleeping or in standby, do nothing. */
> +	if ((dev->flags & ATA_DFLAG_SLEEPING) ||
> +	    !ata_dev_power_is_active(dev))
>  		return;
>  
>  	/*

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH] ata: libata-core: Do not call ata_dev_power_set_standby() twice

[Niklas Cassel]

On Fri, Feb 16, 2024 at 09:16:23PM +0900, Damien Le Moal wrote:
> On 2/16/24 20:20, Niklas Cassel wrote:
> > From: Damien Le Moal <dlemoal@kernel.org>
> > 
> > For regular system shutdown, ata_dev_power_set_standby() will be
> > executed twice: once the scsi device is removed and another when
> > ata_pci_shutdown_one() executes and EH completes unloading the devices.
> > 
> > Make the second call to ata_dev_power_set_standby() do nothing by using
> > ata_dev_power_is_active() and return if the device is already in
> > standby.
> > 
> > Fixes: 2da4c5e24e86 ("ata: libata-core: Improve ata_dev_power_set_active()")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
> > Signed-off-by: Niklas Cassel <cassel@kernel.org>
> > ---
> > This fix was originally part of patch that contained both a fix and
> > a revert in a single patch:
> > https://lore.kernel.org/linux-ide/20240111115123.1258422-3-dlemoal@kernel.org/
> > 
> > This patch contains the only the fix (as it is valid even without the
> > revert), without the revert.
> > 
> > Updated the Fixes tag to point to a more appropriate commit, since we
> > no longer revert any code.
> > 
> >  drivers/ata/libata-core.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> > index d9f80f4f70f5..af2334bc806d 100644
> > --- a/drivers/ata/libata-core.c
> > +++ b/drivers/ata/libata-core.c
> > @@ -85,6 +85,7 @@ static unsigned int ata_dev_init_params(struct ata_device *dev,
> >  static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
> >  static void ata_dev_xfermask(struct ata_device *dev);
> >  static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
> > +static bool ata_dev_power_is_active(struct ata_device *dev);
> 
> I forgot what I did originally but didn't I move the code of
> ata_dev_power_is_active() before ata_dev_power_set_standby() to avoid this
> forward declaration ?
> 
> With that, the code is a little odd as ata_dev_power_is_active() is defined
> between ata_dev_power_set_standby() and ata_dev_power_set_active() but both
> functions use it...

Yes, you moved the function instead of forward declaring it.

But then there was a discussion of why ATA_TFLAG_ISADDR is set in
ata_dev_power_is_active():
https://lore.kernel.org/linux-ide/d63a7b93-d1a3-726e-355c-b4a4608626f4@gmail.com/

And you said that you were going to look in to it:
https://lore.kernel.org/linux-ide/0563322c-4093-4e7d-bb48-61712238494e@kernel.org/

Since this fix does not strictly require any changes to
ata_dev_power_is_active(), and since we already have a bunch of
forward declared functions, I think that forward declaring it is a
good way to avoid this actual fix from falling through the cracks.


Kind regards,
Niklas

Re: [PATCH] ata: libata-core: Do not call ata_dev_power_set_standby() twice

[Damien Le Moal]

On 2/16/24 21:33, Niklas Cassel wrote:
> On Fri, Feb 16, 2024 at 09:16:23PM +0900, Damien Le Moal wrote:
>> On 2/16/24 20:20, Niklas Cassel wrote:
>>> From: Damien Le Moal <dlemoal@kernel.org>
>>>
>>> For regular system shutdown, ata_dev_power_set_standby() will be
>>> executed twice: once the scsi device is removed and another when
>>> ata_pci_shutdown_one() executes and EH completes unloading the devices.
>>>
>>> Make the second call to ata_dev_power_set_standby() do nothing by using
>>> ata_dev_power_is_active() and return if the device is already in
>>> standby.
>>>
>>> Fixes: 2da4c5e24e86 ("ata: libata-core: Improve ata_dev_power_set_active()")
>>> Cc: stable@vger.kernel.org
>>> Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
>>> Signed-off-by: Niklas Cassel <cassel@kernel.org>
>>> ---
>>> This fix was originally part of patch that contained both a fix and
>>> a revert in a single patch:
>>> https://lore.kernel.org/linux-ide/20240111115123.1258422-3-dlemoal@kernel.org/
>>>
>>> This patch contains the only the fix (as it is valid even without the
>>> revert), without the revert.
>>>
>>> Updated the Fixes tag to point to a more appropriate commit, since we
>>> no longer revert any code.
>>>
>>>  drivers/ata/libata-core.c | 6 ++++--
>>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
>>> index d9f80f4f70f5..af2334bc806d 100644
>>> --- a/drivers/ata/libata-core.c
>>> +++ b/drivers/ata/libata-core.c
>>> @@ -85,6 +85,7 @@ static unsigned int ata_dev_init_params(struct ata_device *dev,
>>>  static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
>>>  static void ata_dev_xfermask(struct ata_device *dev);
>>>  static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
>>> +static bool ata_dev_power_is_active(struct ata_device *dev);
>>
>> I forgot what I did originally but didn't I move the code of
>> ata_dev_power_is_active() before ata_dev_power_set_standby() to avoid this
>> forward declaration ?
>>
>> With that, the code is a little odd as ata_dev_power_is_active() is defined
>> between ata_dev_power_set_standby() and ata_dev_power_set_active() but both
>> functions use it...
> 
> Yes, you moved the function instead of forward declaring it.
> 
> But then there was a discussion of why ATA_TFLAG_ISADDR is set in
> ata_dev_power_is_active():
> https://lore.kernel.org/linux-ide/d63a7b93-d1a3-726e-355c-b4a4608626f4@gmail.com/
> 
> And you said that you were going to look in to it:
> https://lore.kernel.org/linux-ide/0563322c-4093-4e7d-bb48-61712238494e@kernel.org/
> 

Ah, yes, I remember now. Let me have a look at this and resend a proper patch, +
another one for the ISADDR cleanup. I really don't want to fix this with that
forward declaration if we can avoid it (and we clearly can here).

> Since this fix does not strictly require any changes to
> ata_dev_power_is_active(), and since we already have a bunch of
> forward declared functions, I think that forward declaring it is a
> good way to avoid this actual fix from falling through the cracks.
> 
> 
> Kind regards,
> Niklas

-- 
Damien Le Moal
Western Digital Research