While runnings s0ix cycling test based on rtc alarm wakeup on ADL-P devices, We found the data from CMOS_READ is not reasonable and causes RTC wake up fail.
With the below changes, we don't see unreasonable data from cmos and issue is gone.
cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 13be2ef: rtc: cmos: Disable irq around direct invocation of cmos_interrupt() 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time() 05a0302: rtc: mc146818: Prevent reading garbage
All of the above patches are landed on 6.0.11 stable kernel I'd like pick the above patches back to 5.10 longterm kernel Thanks
On Wed, Dec 07, 2022 at 11:57:22AM +0800, Kane Chen wrote:
While runnings s0ix cycling test based on rtc alarm wakeup on ADL-P devices, We found the data from CMOS_READ is not reasonable and causes RTC wake up fail.
With the below changes, we don't see unreasonable data from cmos and issue is gone.
Thanks for the analysis, I can queue most of these up. There are two which won't go in:
cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 13be2ef: rtc: cmos: Disable irq around direct invocation of cmos_interrupt() 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ
This one fixes a commit which isn't in the 5.10 tree.
d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time()
This one looks like an optimization.
-----Original Message----- From: Sasha Levin sashal@kernel.org Sent: Wednesday, December 7, 2022 1:13 PM To: Chen, Kane kane.chen@intel.com Cc: stable@vger.kernel.org Subject: Re: [PATCH v1] rtc: cmos: avoid UIP when writing/reading alarm time
On Wed, Dec 07, 2022 at 11:57:22AM +0800, Kane Chen wrote:
While runnings s0ix cycling test based on rtc alarm wakeup on ADL-P devices, We found the data from CMOS_READ is not reasonable and causes
RTC wake up fail.
With the below changes, we don't see unreasonable data from cmos and
issue is gone.
Thanks for the analysis, I can queue most of these up. There are two which won't go in:
cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 13be2ef: rtc: cmos: Disable irq around direct invocation of cmos_interrupt() 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ
This one fixes a commit which isn't in the 5.10 tree.
d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time()
This one looks like an optimization.
--
I'm sorry, I thought dcf257e and 6950d04, 13be2ef are also required to avoid cherry-pick conflict After checking again, dcf257e, 6950d04, 13be2ef are not needed.
Here is the list I would like to pick cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs 05a0302: rtc: mc146818: Prevent reading garbage
Thanks a lot
Thanks, Sasha
W dniu 7.12.2022 o 07:51, Chen, Kane pisze:
-----Original Message----- From: Sasha Levin sashal@kernel.org Sent: Wednesday, December 7, 2022 1:13 PM To: Chen, Kane kane.chen@intel.com Cc: stable@vger.kernel.org Subject: Re: [PATCH v1] rtc: cmos: avoid UIP when writing/reading alarm time
On Wed, Dec 07, 2022 at 11:57:22AM +0800, Kane Chen wrote:
While runnings s0ix cycling test based on rtc alarm wakeup on ADL-P devices, We found the data from CMOS_READ is not reasonable and causes
RTC wake up fail.
With the below changes, we don't see unreasonable data from cmos and
issue is gone.
Thanks for the analysis, I can queue most of these up. There are two which won't go in:
cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 13be2ef: rtc: cmos: Disable irq around direct invocation of cmos_interrupt() 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ
This one fixes a commit which isn't in the 5.10 tree.
d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time()
This one looks like an optimization.
--
I'm sorry, I thought dcf257e and 6950d04, 13be2ef are also required to avoid cherry-pick conflict After checking again, dcf257e, 6950d04, 13be2ef are not needed.
Here is the list I would like to pick cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs 05a0302: rtc: mc146818: Prevent reading garbage
Thanks a lot
Thanks, Sasha
Hello,
I think that you should also pick these patches which fix issues in the series that is prepared for 5.4:
1) commit 7372971c1be5 ("rtc: mc146818-lib: fix signedness bug in mc146818_get_time()")
which fixes d35786b: rtc: mc146818-lib: change return values of mc146818_get_time()
2) commit 13be2efc390a ("rtc: cmos: Disable irq around direct invocation of cmos_interrupt()")
which fixes 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ and is not prepared for 5.4 stable even though it was mentioned above.
3) commit 811f5559270f ("rtc: mc146818-lib: fix locking in mc146818_set_time")
which fixes dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time()
When it comes to these two patches:
cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time
I used to think that the issues they fix were very unlikely to happen in practice, so I did not submit them into stable. So thanks for proving me wrong.
Greetings, Mateusz
On Thu, Dec 08, 2022 at 10:47:17PM +0100, Mateusz Jończyk wrote:
W dniu 7.12.2022 o 07:51, Chen, Kane pisze:
-----Original Message----- From: Sasha Levin sashal@kernel.org Sent: Wednesday, December 7, 2022 1:13 PM To: Chen, Kane kane.chen@intel.com Cc: stable@vger.kernel.org Subject: Re: [PATCH v1] rtc: cmos: avoid UIP when writing/reading alarm time
On Wed, Dec 07, 2022 at 11:57:22AM +0800, Kane Chen wrote:
While runnings s0ix cycling test based on rtc alarm wakeup on ADL-P devices, We found the data from CMOS_READ is not reasonable and causes
RTC wake up fail.
With the below changes, we don't see unreasonable data from cmos and
issue is gone.
Thanks for the analysis, I can queue most of these up. There are two which won't go in:
cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 13be2ef: rtc: cmos: Disable irq around direct invocation of cmos_interrupt() 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ
This one fixes a commit which isn't in the 5.10 tree.
d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time()
This one looks like an optimization.
--
I'm sorry, I thought dcf257e and 6950d04, 13be2ef are also required to avoid cherry-pick conflict After checking again, dcf257e, 6950d04, 13be2ef are not needed.
Here is the list I would like to pick cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs 05a0302: rtc: mc146818: Prevent reading garbage
Thanks a lot
Thanks, Sasha
Hello,
I think that you should also pick these patches which fix issues in the series that is prepared for 5.4:
- commit 7372971c1be5 ("rtc: mc146818-lib: fix signedness bug in mc146818_get_time()")
which fixes d35786b: rtc: mc146818-lib: change return values of mc146818_get_time()
- commit 13be2efc390a ("rtc: cmos: Disable irq around direct invocation of cmos_interrupt()")
which fixes 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ and is not prepared for 5.4 stable even though it was mentioned above.
- commit 811f5559270f ("rtc: mc146818-lib: fix locking in mc146818_set_time")
which fixes dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time()
Ack, will do, thanks.
W dniu 9.12.2022 o 01:37, Sasha Levin pisze:
On Thu, Dec 08, 2022 at 10:47:17PM +0100, Mateusz Jończyk wrote:
W dniu 7.12.2022 o 07:51, Chen, Kane pisze:
-----Original Message----- From: Sasha Levin sashal@kernel.org Sent: Wednesday, December 7, 2022 1:13 PM To: Chen, Kane kane.chen@intel.com Cc: stable@vger.kernel.org Subject: Re: [PATCH v1] rtc: cmos: avoid UIP when writing/reading alarm time
On Wed, Dec 07, 2022 at 11:57:22AM +0800, Kane Chen wrote:
While runnings s0ix cycling test based on rtc alarm wakeup on ADL-P devices, We found the data from CMOS_READ is not reasonable and causes
RTC wake up fail.
With the below changes, we don't see unreasonable data from cmos and
issue is gone.
Thanks for the analysis, I can queue most of these up. There are two which won't go in:
cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 13be2ef: rtc: cmos: Disable irq around direct invocation of cmos_interrupt() 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ
This one fixes a commit which isn't in the 5.10 tree.
d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time()
This one looks like an optimization.
--
I'm sorry, I thought dcf257e and 6950d04, 13be2ef are also required to avoid cherry-pick conflict After checking again, dcf257e, 6950d04, 13be2ef are not needed.
Here is the list I would like to pick cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs 05a0302: rtc: mc146818: Prevent reading garbage
Thanks a lot
Thanks, Sasha
Hello,
I think that you should also pick these patches which fix issues in the series that is prepared for 5.4:
- commit 7372971c1be5 ("rtc: mc146818-lib: fix signedness bug in mc146818_get_time()")
which fixes d35786b: rtc: mc146818-lib: change return values of mc146818_get_time()
- commit 13be2efc390a ("rtc: cmos: Disable irq around direct invocation of cmos_interrupt()")
which fixes 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ and is not prepared for 5.4 stable even though it was mentioned above.
- commit 811f5559270f ("rtc: mc146818-lib: fix locking in mc146818_set_time")
which fixes dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time()
Ack, will do, thanks.
Hello,
However, I would like to ask: is it really necessary to include all of these patches in stable? I think that it is very likely that only these patches are sufficient to fix the original problem reported by Kane Chen:
cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP
These patches should be most relevant when using the RTC alarm and are self-contained. So I would like to ask Kane Chen to recheck with these patches only. Other patches change the CMOS RTC reading routines significantly and have a higher risk of introducing regressions (but I am not aware of any outstanding problems).
The last patch of the three: ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP introduces only a new function; it won't apply cleanly over kernel 5.4, but this is straightforward to fix.
Greetings,
Mateusz
On Fri, Dec 09, 2022 at 11:40:56PM +0100, Mateusz Jończyk wrote:
W dniu 9.12.2022 o 01:37, Sasha Levin pisze:
On Thu, Dec 08, 2022 at 10:47:17PM +0100, Mateusz Jończyk wrote:
W dniu 7.12.2022 o 07:51, Chen, Kane pisze:
-----Original Message----- From: Sasha Levin sashal@kernel.org Sent: Wednesday, December 7, 2022 1:13 PM To: Chen, Kane kane.chen@intel.com Cc: stable@vger.kernel.org Subject: Re: [PATCH v1] rtc: cmos: avoid UIP when writing/reading alarm time
On Wed, Dec 07, 2022 at 11:57:22AM +0800, Kane Chen wrote:
While runnings s0ix cycling test based on rtc alarm wakeup on ADL-P devices, We found the data from CMOS_READ is not reasonable and causes
RTC wake up fail.
With the below changes, we don't see unreasonable data from cmos and
issue is gone.
Thanks for the analysis, I can queue most of these up. There are two which won't go in:
cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 13be2ef: rtc: cmos: Disable irq around direct invocation of cmos_interrupt() 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ
This one fixes a commit which isn't in the 5.10 tree.
d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time()
This one looks like an optimization.
--
I'm sorry, I thought dcf257e and 6950d04, 13be2ef are also required to avoid cherry-pick conflict After checking again, dcf257e, 6950d04, 13be2ef are not needed.
Here is the list I would like to pick cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs 05a0302: rtc: mc146818: Prevent reading garbage
Thanks a lot
Thanks, Sasha
Hello,
I think that you should also pick these patches which fix issues in the series that is prepared for 5.4:
- commit 7372971c1be5 ("rtc: mc146818-lib: fix signedness bug in mc146818_get_time()")
which fixes d35786b: rtc: mc146818-lib: change return values of mc146818_get_time()
- commit 13be2efc390a ("rtc: cmos: Disable irq around direct invocation of cmos_interrupt()")
which fixes 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ and is not prepared for 5.4 stable even though it was mentioned above.
- commit 811f5559270f ("rtc: mc146818-lib: fix locking in mc146818_set_time")
which fixes dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time()
Ack, will do, thanks.
Hello,
However, I would like to ask: is it really necessary to include all of these patches in stable? I think that it is very likely that only these patches are sufficient to fix the original problem reported by Kane Chen:
cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP
I would agree that this could be enough to fix the issue that was described, but...
These patches should be most relevant when using the RTC alarm and are self-contained. So I would like to ask Kane Chen to recheck with these patches only. Other patches change the CMOS RTC reading routines significantly and have a higher risk of introducing regressions (but I am not aware of any outstanding problems).
The rest of the patches do look like fixes that should have been added to stable (or are dependencies of such fixes) on their own. Given those patches are pretty old, any reason to not just include them?
The process works better if we address issues before making users come and complain on the mailing list :)
-----Original Message----- From: Sasha Levin sashal@kernel.org Sent: Sunday, December 11, 2022 2:10 PM To: Mateusz Jończyk mat.jonczyk@o2.pl Cc: Chen, Kane kane.chen@intel.com; stable@vger.kernel.org; Alexandre Belloni alexandre.belloni@bootlin.com Subject: Re: [PATCH v1] rtc: cmos: avoid UIP when writing/reading alarm time
On Fri, Dec 09, 2022 at 11:40:56PM +0100, Mateusz Jończyk wrote:
W dniu 9.12.2022 o 01:37, Sasha Levin pisze:
On Thu, Dec 08, 2022 at 10:47:17PM +0100, Mateusz Jończyk wrote:
W dniu 7.12.2022 o 07:51, Chen, Kane pisze:
-----Original Message----- From: Sasha Levin sashal@kernel.org Sent: Wednesday, December 7, 2022 1:13 PM To: Chen, Kane kane.chen@intel.com Cc: stable@vger.kernel.org Subject: Re: [PATCH v1] rtc: cmos: avoid UIP when writing/reading alarm time
On Wed, Dec 07, 2022 at 11:57:22AM +0800, Kane Chen wrote: > While runnings s0ix cycling test based on rtc alarm wakeup on > ADL-P devices, We found the data from CMOS_READ is not reasonable > and causes RTC wake up fail. > With the below changes, we don't see unreasonable data from cmos > and issue is gone.
Thanks for the analysis, I can queue most of these up. There are two which won't go in:
> cd17420: rtc: cmos: avoid UIP when writing alarm time > cdedc45: rtc: cmos: avoid UIP when reading alarm time > ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP > ea6fa49: rtc: mc146818-lib: fix RTC presence check > 13be2ef: rtc: cmos: Disable irq around direct invocation of > cmos_interrupt() > 0dd8d6c: rtc: Check return value from mc146818_get_time() > e1aba37: rtc: cmos: remove stale REVISIT comments > 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in > hard IRQ This one fixes a commit which isn't in the 5.10 tree.
> d35786b: rtc: mc146818-lib: change return values of > mc146818_get_time() > ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D > 211e5db: rtc: mc146818: Detect and handle broken RTCs > dcf257e: rtc: mc146818: Reduce spinlock section in > mc146818_set_time() This one looks like an optimization.
--
I'm sorry, I thought dcf257e and 6950d04, 13be2ef are also required to avoid cherry-pick conflict After checking again, dcf257e, 6950d04, 13be2ef are
not needed.
Here is the list I would like to pick cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP ea6fa49: rtc: mc146818-lib: fix RTC presence check 0dd8d6c: rtc: Check return value from mc146818_get_time() e1aba37: rtc: cmos: remove stale REVISIT comments d35786b: rtc: mc146818-lib: change return values of mc146818_get_time() ebb22a0: rtc: mc146818: Dont test for bit 0-5 in Register D 211e5db: rtc: mc146818: Detect and handle broken RTCs 05a0302: rtc: mc146818: Prevent reading garbage
Thanks a lot
Thanks, Sasha
Hello,
I think that you should also pick these patches which fix issues in the series that is prepared for 5.4:
- commit 7372971c1be5 ("rtc: mc146818-lib: fix signedness bug in
mc146818_get_time()")
which fixes d35786b: rtc: mc146818-lib: change return values of mc146818_get_time()
- commit 13be2efc390a ("rtc: cmos: Disable irq around direct
invocation of cmos_interrupt()")
which fixes 6950d04: rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ and is not prepared for 5.4 stable even though it was
mentioned above.
- commit 811f5559270f ("rtc: mc146818-lib: fix locking in
mc146818_set_time")
which fixes dcf257e: rtc: mc146818: Reduce spinlock section in mc146818_set_time()
Ack, will do, thanks.
Hello,
However, I would like to ask: is it really necessary to include all of these patches in stable? I think that it is very likely that only these patches are sufficient to fix the original problem reported by Kane Chen:
cd17420: rtc: cmos: avoid UIP when writing alarm time cdedc45: rtc: cmos: avoid UIP when reading alarm time ec5895c: rtc: mc146818-lib: extract mc146818_avoid_UIP
"05a0302: rtc: mc146818: Prevent reading garbage" this helps the issue as well I think.
I didn't test these 3 patches alone because it will create conflicts when I pick ec5895c. I'm worried I made things wrong and thought those dependencies are landed for a long time So decided to pick related dependencies eventually.
Pls let me know if you have concern :)
I would agree that this could be enough to fix the issue that was described, but...
These patches should be most relevant when using the RTC alarm and are self-contained. So I would like to ask Kane Chen to recheck with these patches only. Other patches change the CMOS RTC reading routines significantly and have a higher risk of introducing regressions (but I am not aware of any outstanding problems).
The rest of the patches do look like fixes that should have been added to stable (or are dependencies of such fixes) on their own. Given those patches are pretty old, any reason to not just include them?
The process works better if we address issues before making users come and complain on the mailing list :)
-- Thanks, Sasha
linux-stable-mirror@lists.linaro.org
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Chen, Kane -
Kane Chen
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Mateusz Jończyk -
Sasha Levin