From: Kamel Bouhara <kamel.bouhara@bootlin.com>
To: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 2/4] i2c: at91: implement i2c bus recovery
Date: Tue, 22 Oct 2019 09:59:43 +0200 [thread overview]
Message-ID: <724d3470-0561-1b3f-c826-bc16c74a8c0a@bootlin.com> (raw)
In-Reply-To: <20191021202044.GB3607@kunai>
On 21/10/2019 22:20, Wolfram Sang wrote:
> 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?
>
Indeed, I guess I mess it up while doing some git stuff, it should be
called from at91_do_twi_transfer() when the transfer times out...
I actually tested it and verified the recovery is triggered by pulling
the SCL to the ground ...
> 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?
>
I'm OK to merge the two series.
>
> _______________________________________________
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> linux-arm-kernel@lists.infradead.org
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>
--
Kamel Bouhara, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com
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next prev parent reply other threads:[~2019-10-22 8:00 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
2019-10-21 20:20 ` Wolfram Sang
2019-10-22 7:59 ` Kamel Bouhara [this message]
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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