Re: [PATCH v2 06/11] i2c: nomadik: support short xfer timeouts using waitqueue & hrtimer

[Wolfram Sang <wsa@kernel.org>]

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On Thu, Feb 29, 2024 at 07:10:54PM +0100, Théo Lebrun wrote:
> Replace the completion by a waitqueue for synchronization from IRQ
> handler to task. For short timeouts, use hrtimers, else use timers.
> Usecase: avoid blocking the I2C bus for too long when an issue occurs.
> 
> The threshold picked is one jiffy: if timeout is below that, use
> hrtimers. This threshold is NOT configurable.
> 
> Implement behavior but do NOT change fetching of timeout. This means the
> timeout is unchanged (200ms) and the hrtimer case will never trigger.
> 
> A waitqueue is used because it supports both desired timeout approaches.
> See wait_event_timeout() and wait_event_hrtimeout(). An atomic boolean
> serves as synchronization condition.
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>

Largely:

Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Nit:

> -	int				timeout;
> +	int				timeout_usecs;

I think 'unsigned' makes a lot of sense here. Maybe u32 even?


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