RE: [PATCH v2 1/2] soc: fsl: qbman: Always disable interrupts when taking cgr_lock
> -Original Message-
> From: Sean Anderson
> Sent: Monday, April 3, 2023 18:22
> To: Vladimir Oltean
> Cc: Leo Li ; linuxppc-dev@lists.ozlabs.org; linux-arm-
> ker...@lists.infradead.org; Scott Wood ; Camelia
> Alexandra Groza ; linux-ker...@vger.kernel.org;
> Roy Pledge ; David S . Miller
> ; Claudiu Manoil
> Subject: Re: [PATCH v2 1/2] soc: fsl: qbman: Always disable interrupts when
> taking cgr_lock
>
> On 4/3/23 10:02, Vladimir Oltean wrote:
> > On Fri, Mar 31, 2023 at 11:14:12AM -0400, Sean Anderson wrote:
> >> smp_call_function_single disables IRQs when executing the callback. To
> >> prevent deadlocks, we must disable IRQs when taking cgr_lock elsewhere.
> >> This is already done by qman_update_cgr and qman_delete_cgr; fix the
> >> other lockers.
> >>
> >> Fixes: c535e923bb97 ("soc/fsl: Introduce DPAA 1.x QMan device driver")
> >
> > If you've identified smp_call_function_single() as the problem, then the
> > true issue seems to lie in commit 96f413f47677 ("soc/fsl/qbman: fix
> > issue in qman_delete_cgr_safe()") and not in the initial commit, no?
>
> Yes, that seems better. I did a blame and saw that qman_delete_cgr_safe
> had been around since the initial driver, but I didn't realize it worked
> in a different way back then.
>
> --Sean
>
> > Anyway,
> >
> > Tested-by: Vladimir Oltean
Apart from Vladimir's comment:
Reviewed-by: Camelia Groza
Re: [PATCH v2 1/2] soc: fsl: qbman: Always disable interrupts when taking cgr_lock
On 4/3/23 10:02, Vladimir Oltean wrote:
> On Fri, Mar 31, 2023 at 11:14:12AM -0400, Sean Anderson wrote:
>> smp_call_function_single disables IRQs when executing the callback. To
>> prevent deadlocks, we must disable IRQs when taking cgr_lock elsewhere.
>> This is already done by qman_update_cgr and qman_delete_cgr; fix the
>> other lockers.
>>
>> Fixes: c535e923bb97 ("soc/fsl: Introduce DPAA 1.x QMan device driver")
>
> If you've identified smp_call_function_single() as the problem, then the
> true issue seems to lie in commit 96f413f47677 ("soc/fsl/qbman: fix
> issue in qman_delete_cgr_safe()") and not in the initial commit, no?
Yes, that seems better. I did a blame and saw that qman_delete_cgr_safe
had been around since the initial driver, but I didn't realize it worked
in a different way back then.
--Sean
> Anyway,
>
> Tested-by: Vladimir Oltean
Re: [PATCH v2 1/2] soc: fsl: qbman: Always disable interrupts when taking cgr_lock
On Fri, Mar 31, 2023 at 11:14:12AM -0400, Sean Anderson wrote:
> smp_call_function_single disables IRQs when executing the callback. To
> prevent deadlocks, we must disable IRQs when taking cgr_lock elsewhere.
> This is already done by qman_update_cgr and qman_delete_cgr; fix the
> other lockers.
>
> Fixes: c535e923bb97 ("soc/fsl: Introduce DPAA 1.x QMan device driver")
If you've identified smp_call_function_single() as the problem, then the
true issue seems to lie in commit 96f413f47677 ("soc/fsl/qbman: fix
issue in qman_delete_cgr_safe()") and not in the initial commit, no?
Anyway,
Tested-by: Vladimir Oltean
