[RFC PATCH] Revert "mwifiex: fix system hang problem after resume"

[RFC PATCH] Revert "mwifiex: fix system hang problem after resume"

[Brian Norris]

This reverts commit 437322ea2a36d112e20aa7282c869bf924b3a836.

This above-mentioned "fix" does not actually do anything to prevent a
race condition. It simply papers over it so that the issue doesn't
appear.

If this is a real problem, it should be explained better than the above
commit does, and an alternative, non-racy solution should be found.

For further reason to revert this: there's ot reason we can't try
resetting the card when it's *actually* stuck in host-sleep mode. So
instead, this is unnecessarily creating scenarios where we can't recover
Wifi.

Cc: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Brian Norris <briannorris@chromium.org>
---
Amit, please take a look. AIUI, your "fix" is wrong, and quite racy. If you
still think it's needed, can you please propose an alternative? Or at least
explain more why this is needed? Thanks.

 drivers/net/wireless/marvell/mwifiex/init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/init.c b/drivers/net/wireless/marvell/mwifiex/init.c
index 756948385b60..0dab77b526de 100644
--- a/drivers/net/wireless/marvell/mwifiex/init.c
+++ b/drivers/net/wireless/marvell/mwifiex/init.c
@@ -60,7 +60,7 @@ static void wakeup_timer_fn(unsigned long data)
 	adapter->hw_status = MWIFIEX_HW_STATUS_RESET;
 	mwifiex_cancel_all_pending_cmd(adapter);
 
-	if (adapter->if_ops.card_reset && !adapter->hs_activated)
+	if (adapter->if_ops.card_reset)
 		adapter->if_ops.card_reset(adapter);
 }
 
-- 
2.12.2.564.g063fe858b8-goog

Re: [RFC PATCH] Revert "mwifiex: fix system hang problem after resume"

[Dmitry Torokhov]

On Fri, Mar 31, 2017 at 01:21:36PM -0700, Brian Norris wrote:
> This reverts commit 437322ea2a36d112e20aa7282c869bf924b3a836.
> 
> This above-mentioned "fix" does not actually do anything to prevent a
> race condition. It simply papers over it so that the issue doesn't
> appear.
> 
> If this is a real problem, it should be explained better than the above
> commit does, and an alternative, non-racy solution should be found.
> 
> For further reason to revert this: there's ot reason we can't try
> resetting the card when it's *actually* stuck in host-sleep mode. So
> instead, this is unnecessarily creating scenarios where we can't recover
> Wifi.
> 
> Cc: Amitkumar Karwar <akarwar@marvell.com>
> Signed-off-by: Brian Norris <briannorris@chromium.org>

FWIW:

Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

> ---
> Amit, please take a look. AIUI, your "fix" is wrong, and quite racy. If you
> still think it's needed, can you please propose an alternative? Or at least
> explain more why this is needed? Thanks.
> 
>  drivers/net/wireless/marvell/mwifiex/init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/marvell/mwifiex/init.c b/drivers/net/wireless/marvell/mwifiex/init.c
> index 756948385b60..0dab77b526de 100644
> --- a/drivers/net/wireless/marvell/mwifiex/init.c
> +++ b/drivers/net/wireless/marvell/mwifiex/init.c
> @@ -60,7 +60,7 @@ static void wakeup_timer_fn(unsigned long data)
>  	adapter->hw_status = MWIFIEX_HW_STATUS_RESET;
>  	mwifiex_cancel_all_pending_cmd(adapter);
>  
> -	if (adapter->if_ops.card_reset && !adapter->hs_activated)
> +	if (adapter->if_ops.card_reset)
>  		adapter->if_ops.card_reset(adapter);
>  }
>  
> -- 
> 2.12.2.564.g063fe858b8-goog
> 

-- 
Dmitry

Re: [RFC PATCH] Revert "mwifiex: fix system hang problem after resume"

[amit karwar]

On Sat, Apr 1, 2017 at 1:51 AM, Brian Norris <briannorris@chromium.org> wrote:
> This reverts commit 437322ea2a36d112e20aa7282c869bf924b3a836.
>
> This above-mentioned "fix" does not actually do anything to prevent a
> race condition. It simply papers over it so that the issue doesn't
> appear.
>
> If this is a real problem, it should be explained better than the above
> commit does, and an alternative, non-racy solution should be found.
>
> For further reason to revert this: there's ot reason we can't try
> resetting the card when it's *actually* stuck in host-sleep mode. So
> instead, this is unnecessarily creating scenarios where we can't recover
> Wifi.
>
> Cc: Amitkumar Karwar <akarwar@marvell.com>
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> ---
> Amit, please take a look. AIUI, your "fix" is wrong, and quite racy. If you
> still think it's needed, can you please propose an alternative? Or at least
> explain more why this is needed? Thanks.
>

I agree. Fix just covers the issue. We need to investigate why system
hangs when card reset is attempted in host sleep activated scenario.

Acked-by: Amitkumar Karwar <amitkarwar@gmail.com>

Regards,
Amitkumar Karwar

Re: [RFC PATCH] Revert "mwifiex: fix system hang problem after resume"

[Brian Norris]

+ Doug, Matthias, who are seeing problems (or, failure to try to
recover, as predicted below)
+ Amit's new email
+ new maintainers

Perhaps it's my fault for marking this RFC. But I changed the status
back to "New" in Patchwork, in case that helps:

On Fri, Mar 31, 2017 at 01:21:36PM -0700, Brian Norris wrote:
> This reverts commit 437322ea2a36d112e20aa7282c869bf924b3a836.
> 
> This above-mentioned "fix" does not actually do anything to prevent a
> race condition. It simply papers over it so that the issue doesn't
> appear.
> 
> If this is a real problem, it should be explained better than the above
> commit does, and an alternative, non-racy solution should be found.
> 
> For further reason to revert this: there's ot reason we can't try

s/ot/no/

...oops.

> resetting the card when it's *actually* stuck in host-sleep mode. So
> instead, this is unnecessarily creating scenarios where we can't recover
> Wifi.
> 
> Cc: Amitkumar Karwar <akarwar@marvell.com>
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> ---
> Amit, please take a look. AIUI, your "fix" is wrong, and quite racy. If you
> still think it's needed, can you please propose an alternative? Or at least
> explain more why this is needed? Thanks.

FWIW, I got an Acked-by from Amit when he was still at Marvell. And
another Reviewed-by from Dmitry. This still applies. Should I resend?
(I'll do that if I don't hear a response within a few days.)

Thanks,
Brian

>  drivers/net/wireless/marvell/mwifiex/init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/marvell/mwifiex/init.c b/drivers/net/wireless/marvell/mwifiex/init.c
> index 756948385b60..0dab77b526de 100644
> --- a/drivers/net/wireless/marvell/mwifiex/init.c
> +++ b/drivers/net/wireless/marvell/mwifiex/init.c
> @@ -60,7 +60,7 @@ static void wakeup_timer_fn(unsigned long data)
>  	adapter->hw_status = MWIFIEX_HW_STATUS_RESET;
>  	mwifiex_cancel_all_pending_cmd(adapter);
>  
> -	if (adapter->if_ops.card_reset && !adapter->hs_activated)
> +	if (adapter->if_ops.card_reset)
>  		adapter->if_ops.card_reset(adapter);
>  }
>  
> -- 
> 2.12.2.564.g063fe858b8-goog
> 

Re: [RFC PATCH] Revert "mwifiex: fix system hang problem after resume"

[Kalle Valo]

Brian Norris <briannorris@chromium.org> writes:

> + Doug, Matthias, who are seeing problems (or, failure to try to
> recover, as predicted below)
> + Amit's new email
> + new maintainers
>
> Perhaps it's my fault for marking this RFC. But I changed the status
> back to "New" in Patchwork, in case that helps:

But I still see it marked as RFC. So the patch in question is:

https://patchwork.kernel.org/patch/9657277/

Changing the patchwork state to RFC means that it's dropped and out of
my radar. Also, if I see "RFC" in the subject I assume that's a patch
which I should not apply by default.

> On Fri, Mar 31, 2017 at 01:21:36PM -0700, Brian Norris wrote:
>> This reverts commit 437322ea2a36d112e20aa7282c869bf924b3a836.
>> 
>> This above-mentioned "fix" does not actually do anything to prevent a
>> race condition. It simply papers over it so that the issue doesn't
>> appear.
>> 
>> If this is a real problem, it should be explained better than the above
>> commit does, and an alternative, non-racy solution should be found.
>> 
>> For further reason to revert this: there's ot reason we can't try
>
> s/ot/no/
>
> ...oops.
>
>> resetting the card when it's *actually* stuck in host-sleep mode. So
>> instead, this is unnecessarily creating scenarios where we can't recover
>> Wifi.
>> 
>> Cc: Amitkumar Karwar <akarwar@marvell.com>
>> Signed-off-by: Brian Norris <briannorris@chromium.org>
>> ---
>> Amit, please take a look. AIUI, your "fix" is wrong, and quite racy. If you
>> still think it's needed, can you please propose an alternative? Or at least
>> explain more why this is needed? Thanks.
>
> FWIW, I got an Acked-by from Amit when he was still at Marvell. And
> another Reviewed-by from Dmitry. This still applies. Should I resend?
> (I'll do that if I don't hear a response within a few days.)

This patch is from 2017 so better to resend, and without RFC markings.

-- 
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: [RFC PATCH] Revert "mwifiex: fix system hang problem after resume"

[Brian Norris]

On Fri, Aug 2, 2019 at 6:55 PM Kalle Valo <kvalo@codeaurora.org> wrote:
>
> Brian Norris <briannorris@chromium.org> writes:
>
> > + Doug, Matthias, who are seeing problems (or, failure to try to
> > recover, as predicted below)
> > + Amit's new email
> > + new maintainers
> >
> > Perhaps it's my fault for marking this RFC. But I changed the status
> > back to "New" in Patchwork, in case that helps:
>
> But I still see it marked as RFC. So the patch in question is:
>
> https://patchwork.kernel.org/patch/9657277/

Oops, I didn't hit the "Update" button :(

I changed it now, but I'll change it back again.

> Changing the patchwork state to RFC means that it's dropped and out of
> my radar. Also, if I see "RFC" in the subject I assume that's a patch
> which I should not apply by default.

Ack. Well, there were some "RFCs" I sent recently that you *did*
apply, so I didn't really know what happens normally.

> > On Fri, Mar 31, 2017 at 01:21:36PM -0700, Brian Norris wrote:
...
> > FWIW, I got an Acked-by from Amit when he was still at Marvell. And
> > another Reviewed-by from Dmitry. This still applies. Should I resend?
> > (I'll do that if I don't hear a response within a few days.)
>
> This patch is from 2017 so better to resend, and without RFC markings.

Yep, will do.

Brian

Re: [RFC PATCH] Revert "mwifiex: fix system hang problem after resume"

[Kalle Valo]

Brian Norris <briannorris@chromium.org> writes:

>> Changing the patchwork state to RFC means that it's dropped and out of
>> my radar. Also, if I see "RFC" in the subject I assume that's a patch
>> which I should not apply by default.
>
> Ack. Well, there were some "RFCs" I sent recently that you *did*
> apply, so I didn't really know what happens normally.

True, I have sometimes applied RFC patches in case they look good enough
and I do not want them to get lost (and this is a good example of RFC
patches getting lost). But by default I drop RFC patches after a quick
glance.

>> > On Fri, Mar 31, 2017 at 01:21:36PM -0700, Brian Norris wrote:
> ...
>> > FWIW, I got an Acked-by from Amit when he was still at Marvell. And
>> > another Reviewed-by from Dmitry. This still applies. Should I resend?
>> > (I'll do that if I don't hear a response within a few days.)
>>
>> This patch is from 2017 so better to resend, and without RFC markings.
>
> Yep, will do.

Thanks.

-- 
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches