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From: "Théo Lebrun" <theo.lebrun@bootlin.com>
To: "Wolfram Sang" <wsa@kernel.org>
Cc: "Linus Walleij" <linus.walleij@linaro.org>,
	"Andi Shyti" <andi.shyti@kernel.org>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Thomas Bogendoerfer" <tsbogend@alpha.franken.de>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-i2c@vger.kernel.org>, <devicetree@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <linux-mips@vger.kernel.org>,
	"Gregory Clement" <gregory.clement@bootlin.com>,
	"Vladimir Kondratiev" <vladimir.kondratiev@mobileye.com>,
	"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>,
	"Tawfik Bayouk" <tawfik.bayouk@mobileye.com>
Subject: Re: [PATCH v2 06/11] i2c: nomadik: support short xfer timeouts using waitqueue & hrtimer
Date: Mon, 04 Mar 2024 11:14:53 +0100	[thread overview]
Message-ID: <CZKVXSULAGXC.1C5PDQJ6KCHN@bootlin.com> (raw)
In-Reply-To: <ZeWRyuN8v-VnraQA@ninjato>

Hello,

On Mon Mar 4, 2024 at 10:18 AM CET, Wolfram Sang wrote:
> 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>

Thanks for the reviews Wolfram.

> Nit:
>
> > -	int				timeout;
> > +	int				timeout_usecs;
>
> I think 'unsigned' makes a lot of sense here. Maybe u32 even?

Yes unsigned would make sense. unsigned int or u32, I wouldn't know
which to pick.

Regards,

--
Théo Lebrun, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com


  reply	other threads:[~2024-03-04 10:14 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-29 18:10 [PATCH v2 00/11] Add Mobileye EyeQ5 support to the Nomadik I2C controller & use hrtimers for timeouts Théo Lebrun
2024-02-29 18:10 ` [PATCH v2 01/11] dt-bindings: i2c: nomadik: add mobileye,eyeq5-i2c bindings and example Théo Lebrun
2024-02-29 19:26   ` Rob Herring
2024-03-01 15:11   ` Rob Herring
2024-03-01 15:47     ` Théo Lebrun
2024-02-29 18:10 ` [PATCH v2 02/11] dt-bindings: hwmon: lm75: use common hwmon schema Théo Lebrun
2024-02-29 19:26   ` Rob Herring
2024-03-01  6:37   ` Krzysztof Kozlowski
2024-03-01  6:53     ` Guenter Roeck
2024-03-01  9:41       ` Théo Lebrun
2024-03-01 10:13         ` Krzysztof Kozlowski
2024-03-01 10:44           ` Théo Lebrun
2024-03-01 11:35             ` Krzysztof Kozlowski
2024-03-01 14:09               ` Théo Lebrun
2024-03-01 14:13                 ` Krzysztof Kozlowski
2024-03-01 15:35             ` Rob Herring
2024-03-01 15:52               ` Théo Lebrun
2024-03-01 15:38       ` Rob Herring
2024-03-01 19:21   ` Guenter Roeck
2024-02-29 18:10 ` [PATCH v2 03/11] i2c: nomadik: rename private struct pointers from dev to priv Théo Lebrun
2024-03-02  0:16   ` [SPAM] " Andi Shyti
2024-03-04  9:13   ` Wolfram Sang
2024-02-29 18:10 ` [PATCH v2 04/11] i2c: nomadik: simplify IRQ masking logic Théo Lebrun
2024-03-02  0:39   ` [SPAM] " Andi Shyti
2024-03-04  9:46     ` Théo Lebrun
2024-02-29 18:10 ` [PATCH v2 05/11] i2c: nomadik: use bitops helpers Théo Lebrun
2024-03-02  1:31   ` Andi Shyti
2024-03-04 10:00     ` Théo Lebrun
2024-02-29 18:10 ` [PATCH v2 06/11] i2c: nomadik: support short xfer timeouts using waitqueue & hrtimer Théo Lebrun
2024-03-04  9:18   ` Wolfram Sang
2024-03-04 10:14     ` Théo Lebrun [this message]
2024-03-04 11:37       ` Wolfram Sang
2024-03-04 13:54   ` [SPAM] " Andi Shyti
2024-03-04 14:32     ` Théo Lebrun
2024-03-04 15:09       ` Andi Shyti
2024-02-29 18:10 ` [PATCH v2 07/11] i2c: nomadik: replace jiffies by ktime for FIFO flushing timeout Théo Lebrun
2024-03-04  9:23   ` Wolfram Sang
2024-03-04 13:55   ` Andi Shyti
2024-02-29 18:10 ` [PATCH v2 08/11] i2c: nomadik: fetch i2c-transfer-timeout-us property from devicetree Théo Lebrun
2024-02-29 21:04   ` Linus Walleij
2024-03-04  9:25   ` Wolfram Sang
2024-03-04 13:57   ` Andi Shyti
2024-02-29 18:10 ` [PATCH v2 09/11] i2c: nomadik: support Mobileye EyeQ5 I2C controller Théo Lebrun
2024-02-29 21:08   ` Linus Walleij
2024-03-04  9:27   ` Wolfram Sang
2024-03-04 10:25     ` Théo Lebrun
2024-03-04 14:08   ` Andi Shyti
2024-03-04 14:53     ` Théo Lebrun
2024-02-29 18:10 ` [PATCH v2 10/11] MIPS: mobileye: eyeq5: add 5 I2C controller nodes Théo Lebrun
2024-02-29 21:09   ` Linus Walleij
2024-02-29 18:10 ` [PATCH v2 11/11] MIPS: mobileye: eyeq5: add evaluation board I2C temp sensor Théo Lebrun
2024-02-29 21:09   ` Linus Walleij
2024-03-06  1:49 ` [PATCH v2 00/11] Add Mobileye EyeQ5 support to the Nomadik I2C controller & use hrtimers for timeouts Andi Shyti
2024-03-06  9:34   ` Théo Lebrun

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