Re: [PATCH v2 2/2] i2c: tegra: make tegra_i2c_mutex_unlock() return void

[Jon Hunter <jonathanh@nvidia.com>]

On 08/05/2026 11:24, Thierry Reding wrote:
> On Thu, May 07, 2026 at 10:11:45PM +0000, Saurav Sachidanand wrote:
>> tegra_i2c_mutex_unlock() returning an error that overwrites the transfer
>> result causes silent loss of I2C transfer errors. If the transfer failed
>> but the unlock succeeded, the error was lost and the function incorrectly
>> reported success.
>>
>> Rather than propagating the unlock error (which is not actionable by the
>> caller - the I2C message may have been sent regardless), convert the
>> function to return void and WARN on the unexpected condition. If the
>> unlock fails, subsequent lock attempts will fail anyway, making the error
>> visible on the next transfer.
> 
> Technically I don't think it's guaranteed that a subsequent lock attempt
> will fail. For example, if the SW mutex was somehow held by some other
> owner while trying to unlock, by the time we try to lock later on that
> owner might have released the SW mutex again.
> 
> Obviously if we've managed to lock the SW mutex but fail to unlock
> because somebody else was holding it, it means that the other party did
> not respect the SW mutex protocol, in which case anything goes.
> 
> Anyway, this looks good to me, so:
> 
> Acked-by: Thierry Reding <treding@nvidia.com>


Reviewed-by: Jon Hunter <jonathanh@nvidia.com>

Thanks
Jon

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