[alsa-devel] [PATCH linux-next v2 1/2] ASoC: rsnd: src: Avoid a potential deadlock

[Jiada Wang]

Hi Fabrizio

On 2019/03/14 3:19, Fabrizio Castro wrote:
> Hello Jiada,
> 
>> From: Jiada Wang <jiada_wang at mentor.com>
>> Sent: 13 March 2019 11:56
>> Subject: Re: [PATCH linux-next v2 1/2] ASoC: rsnd: src: Avoid a potential deadlock
>>
>> Hi Geert
>>
>> On 2019/03/12 18:15, Geert Uytterhoeven wrote:
>>> Hi Jiada, Fabrizio,
>>>
>>> On Thu, Mar 7, 2019 at 7:17 AM Jiada Wang <jiada_wang at mentor.com> wrote:
>>>> lockdep warns us that priv->lock and k->k_lock can cause a
>>>> deadlock when after acquire of k->k_lock, process is interrupted
>>>> by src, while in another routine of src .init, k->k_lock is
>>>> acquired with priv->lock held.
>>>>
>>>> This patch avoids a potential deadlock by not calling soc_device_match()
>>>> in SRC .init callback, instead it adds new soc fields in priv->flags to
>>>> differentiate SoCs.
>>>>
>>>> Fixes: linux-next commit 7674bec4fc09 ("ASoC: rsnd: update BSDSR/BSDISR handling")
>>>> Signed-off-by: Jiada Wang <jiada_wang at mentor.com>
>>>> ---
>>>>    sound/soc/sh/rcar/core.c | 2 ++
>>>>    sound/soc/sh/rcar/rsnd.h | 5 +++++
>>>>    sound/soc/sh/rcar/src.c  | 9 +--------
>>>>    3 files changed, 8 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/sound/soc/sh/rcar/core.c b/sound/soc/sh/rcar/core.c
>>>> index 022996d2db13..4fe83e611c01 100644
>>>> --- a/sound/soc/sh/rcar/core.c
>>>> +++ b/sound/soc/sh/rcar/core.c
>>>> @@ -110,6 +110,8 @@ static const struct of_device_id rsnd_of_match[] = {
>>>>           { .compatible = "renesas,rcar_sound-gen1", .data = (void *)RSND_GEN1 },
>>>>           { .compatible = "renesas,rcar_sound-gen2", .data = (void *)RSND_GEN2 },
>>>>           { .compatible = "renesas,rcar_sound-gen3", .data = (void *)RSND_GEN3 },
>>>> +       /* Special Handling */
>>>> +       { .compatible = "renesas,rcar_sound-r8a77990", .data = (void *)(RSND_GEN3 | RSND_SOC_E) },
>>>
>>> I guess we need an entry for RZ/G2E, too?
> 
> Geert has a point, I am looking at the User manual for the RZ/G2E and it looks like the
> implementation for the RZ/G2E is the same as the one for the r8a77990
> 
>>>
>> Sorry, I don't have user manual for RZ/G2E,
>> if you can let me know where to find RZ/G2E's user manual,
>> I can add entry for these SoCs
> 
> If you prefer I could add that after running some tests? I do have a board with a RZ/G2E.
> 
Yes, please
since I have neither RZ/G2E board to test nor its user manual

Thanks,
Jiada
> Thanks,
> Fab
> 
>>
>> Thanks,
>> Jiada
>>> Gr{oetje,eeting}s,
>>>
>>>                           Geert
>>>