Re: [PATCH v3 5/5] gpu: nova-core: gsp: add mutex locking to Cmdq

[Alexandre Courbot]

On Thu Mar 5, 2026 at 10:36 AM JST, Eliot Courtney wrote:
> On Wed Mar 4, 2026 at 8:57 PM JST, Alexandre Courbot wrote:
>> On Wed Mar 4, 2026 at 11:46 AM JST, Eliot Courtney wrote:
>>> Wrap `Cmdq`'s mutable state in a new struct `CmdqInner` and wrap that in
>>> a Mutex. This lets `Cmdq` methods take &self instead of &mut self, which
>>> lets required commands be sent e.g. while unloading the driver.
>>>
>>> The mutex is held over both send and receive in `send_command` to make
>>> sure that it doesn't get the reply of some other command that could have
>>> been sent just beforehand.
>>>
>>> Reviewed-by: Zhi Wang <zhiw@xxxxxxxxxx>
>>> Tested-by: Zhi Wang <zhiw@xxxxxxxxxx>
>>> Signed-off-by: Eliot Courtney <ecourtney@xxxxxxxxxx>
>>> ---
>>>  drivers/gpu/nova-core/gsp/boot.rs      |   8 +-
>>>  drivers/gpu/nova-core/gsp/cmdq.rs      | 247 +++++++++++++++++++--------------
>>>  drivers/gpu/nova-core/gsp/commands.rs  |   4 +-
>>>  drivers/gpu/nova-core/gsp/sequencer.rs |   2 +-
>>>  4 files changed, 146 insertions(+), 115 deletions(-)
>>
>> Most of the diff is code moving around. I've been able to reduce it to
>> +107 -76 by moving `CmdqInner` *after* `Cmdq` - this makes this patch
>> easier to review imho.
>
> Thanks, will move this then since I think the ordering here is probably
> not too important to readability.

Yes, actually one could even argue in favor of having the public struct
before its inner private counterpart for readability purposes.