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From: Wolfram Sang <wsa@the-dreams.de>
To: Kamel Bouhara <kamel.bouhara@bootlin.com>
Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
	Nicolas Ferre <nicolas.ferre@microchip.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Ludovic Desroches <ludovic.desroches@microchip.com>,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: Re: [PATCH 2/4] i2c: at91: implement i2c bus recovery
Date: Mon, 21 Oct 2019 22:20:44 +0200	[thread overview]
Message-ID: <20191021202044.GB3607@kunai> (raw)
In-Reply-To: <20191002144658.7718-3-kamel.bouhara@bootlin.com>

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On Wed, Oct 02, 2019 at 04:46:56PM +0200, Kamel Bouhara wrote:
> Implement i2c bus recovery when slaves devices might hold SDA low.
> In this case re-assign SCL/SDA to gpios and issue 9 dummy clock pulses
> until the slave release SDA.
> 
> Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>

Setting up the bus_recovery looks OK. However, I don't see any call to
i2c_recover_bus(), so the bus_recovery is never used. Did you test this
and see an effect?

Also, I think we should merge this patch "[PATCH v3] i2c: at91: Send bus
clear command if SCL or SDA is down" into this series. The crucial thing
for both is when to apply the recovery (at the beginning of a
transfer!). The rest is "just" that some HW needs a bus_recovery_info
for pinctrl/GPIO handling (from this patch), while other HW needs a
bus_recovery_info with a custom recover_bus callback.

Opinions?


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WARNING: multiple messages have this Message-ID (diff)
From: Wolfram Sang <wsa@the-dreams.de>
To: Kamel Bouhara <kamel.bouhara@bootlin.com>
Cc: devicetree@vger.kernel.org,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	linux-kernel@vger.kernel.org,
	Ludovic Desroches <ludovic.desroches@microchip.com>,
	linux-i2c@vger.kernel.org,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 2/4] i2c: at91: implement i2c bus recovery
Date: Mon, 21 Oct 2019 22:20:44 +0200	[thread overview]
Message-ID: <20191021202044.GB3607@kunai> (raw)
In-Reply-To: <20191002144658.7718-3-kamel.bouhara@bootlin.com>


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On Wed, Oct 02, 2019 at 04:46:56PM +0200, Kamel Bouhara wrote:
> Implement i2c bus recovery when slaves devices might hold SDA low.
> In this case re-assign SCL/SDA to gpios and issue 9 dummy clock pulses
> until the slave release SDA.
> 
> Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>

Setting up the bus_recovery looks OK. However, I don't see any call to
i2c_recover_bus(), so the bus_recovery is never used. Did you test this
and see an effect?

Also, I think we should merge this patch "[PATCH v3] i2c: at91: Send bus
clear command if SCL or SDA is down" into this series. The crucial thing
for both is when to apply the recovery (at the beginning of a
transfer!). The rest is "just" that some HW needs a bus_recovery_info
for pinctrl/GPIO handling (from this patch), while other HW needs a
bus_recovery_info with a custom recover_bus callback.

Opinions?


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  parent reply	other threads:[~2019-10-21 20:20 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-02 14:46 [PATCH 0/4] i2c bus recovery for Microchip SoCs Kamel Bouhara
2019-10-02 14:46 ` Kamel Bouhara
2019-10-02 14:46 ` [PATCH 1/4] dt-bindings: i2c: at91: document optional bus recovery properties Kamel Bouhara
2019-10-02 14:46   ` Kamel Bouhara
2019-10-02 14:46 ` [PATCH 2/4] i2c: at91: implement i2c bus recovery Kamel Bouhara
2019-10-02 14:46   ` Kamel Bouhara
2019-10-04  9:35   ` Claudiu.Beznea
2019-10-04  9:35     ` Claudiu.Beznea
2019-10-04  9:35     ` Claudiu.Beznea
2019-10-04 20:39     ` Uwe Kleine-König
2019-10-04 20:39       ` Uwe Kleine-König
2019-10-07 10:17       ` Claudiu.Beznea
2019-10-07 10:17         ` Claudiu.Beznea
2019-10-07 10:17         ` Claudiu.Beznea
2019-10-09 13:55   ` Ludovic Desroches
2019-10-09 13:55     ` Ludovic Desroches
2019-10-09 13:55     ` Ludovic Desroches
2019-10-09 14:01     ` Alexandre Belloni
2019-10-09 14:01       ` Alexandre Belloni
2019-10-10  6:54       ` Ludovic Desroches
2019-10-10  6:54         ` Ludovic Desroches
2019-10-10  6:54         ` Ludovic Desroches
2019-10-24 12:29         ` Kamel Bouhara
2019-10-25  7:04           ` Ludovic.Desroches
2019-10-21 20:20   ` Wolfram Sang [this message]
2019-10-21 20:20     ` Wolfram Sang
2019-10-22  7:59     ` Kamel Bouhara
2019-10-24 14:08       ` Codrin.Ciubotariu
2019-10-24 14:08         ` Codrin.Ciubotariu
2019-10-24 14:08         ` Codrin.Ciubotariu
2019-10-24 15:07         ` Wolfram Sang
2019-10-24 15:07           ` Wolfram Sang
2019-10-25  1:14           ` Phil Reid
2019-10-25  1:14             ` Phil Reid
2019-10-25  1:14             ` Phil Reid
2020-08-25 13:28             ` Wolfram Sang
2020-08-25 13:28               ` Wolfram Sang
2020-08-25 23:44               ` Phil Reid
2020-08-25 23:44                 ` Phil Reid
2019-10-02 14:46 ` [PATCH 3/4] ARM: at91/dt: sama5d3: add i2c gpio pinctrl Kamel Bouhara
2019-10-02 14:46   ` Kamel Bouhara
2019-10-02 14:46 ` [PATCH 4/4] ARM: at91/dt: sama5d4: " Kamel Bouhara
2019-10-02 14:46   ` Kamel Bouhara
2019-10-15 19:10 ` [PATCH 0/4] i2c bus recovery for Microchip SoCs Rob Herring
2019-10-15 19:10   ` Rob Herring

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