Re: [PATCH v2] i2c: tegra: Wait for config load atomically while in ISR

[Dmitry Osipenko <digetx@gmail.com>]

11.01.2021 19:08, Mikko Perttunen пишет:
> Upon a communication error, the interrupt handler can call
> tegra_i2c_disable_packet_mode. This causes a sleeping poll to happen
> unless the current transaction was marked atomic. Fix this by
> making the poll happen atomically if we are in an IRQ.
> 
> This matches the behavior prior to the patch mentioned
> in the Fixes tag.
> 
> Fixes: ede2299f7101 ("i2c: tegra: Support atomic transfers")
> Cc: stable@vger.kernel.org
> Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
> ---
> v2:
> * Use in_irq() instead of passing a flag from the ISR.
>   Thanks to Dmitry for the suggestion.
> * Update commit message.
> ---
>  drivers/i2c/busses/i2c-tegra.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index 6f08c0c3238d..0727383f4940 100644
> --- a/drivers/i2c/busses/i2c-tegra.c
> +++ b/drivers/i2c/busses/i2c-tegra.c
> @@ -533,7 +533,7 @@ static int tegra_i2c_poll_register(struct tegra_i2c_dev *i2c_dev,
>  	void __iomem *addr = i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg);
>  	u32 val;
>  
> -	if (!i2c_dev->atomic_mode)
> +	if (!i2c_dev->atomic_mode && !in_irq())
>  		return readl_relaxed_poll_timeout(addr, val, !(val & mask),
>  						  delay_us, timeout_us);
>  
> 

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>