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From: Heiko Schocher <hs@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 1/3] i2c: tegra: use repeated start for reads
Date: Thu, 03 Jul 2014 06:34:45 +0200	[thread overview]
Message-ID: <53B4DD65.1050302@denx.de> (raw)
In-Reply-To: <53B45156.1090202@wwwdotorg.org>

Hello Stephen,

Am 02.07.2014 20:37, schrieb Stephen Warren:
> On 06/25/2014 10:57 AM, Stephen Warren wrote:
>> From: Stephen Warren<swarren@nvidia.com>
>>
>> I2C read transactions are typically implemented as follows:
>>
>> START(write) address REPEATED_START(read) data... STOP
>>
>> However, Tegra's I2C driver currently implements reads as follows:
>>
>> START(write) address STOP START(read) data... STOP
>>
>> This sequence confuses at least the AS3722 PMIC on the Jetson TK1 board,
>> leading to corrupted read data in some cases. Fix the driver to chain
>> the transactions together using repeated starts to solve this.
>
> Heiko, do these patches look good?

Yes, they look good to me... Hmm.. as you ask, I think you want to have
them in v2014.07 ? As it is a bugfix it should go into it, but as it
also changes the behaviour of the driver, I am unsure if it can go in
so close before the new release ... some Tested-by would be nice ...

I applied them to the u-boot-i2c.git tree, and if nobody objects
against them, I send tomorrow a pull request to Tom.

bye,
Heiko
-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

  reply	other threads:[~2014-07-03  4:34 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-25 16:57 [U-Boot] [PATCH 1/3] i2c: tegra: use repeated start for reads Stephen Warren
2014-06-25 16:57 ` [U-Boot] [PATCH 2/3] i2c: tegra: write clean data to TX FIFO Stephen Warren
2014-06-25 23:37   ` Yen Lin
2014-06-25 23:42   ` Yen Lin
2014-06-25 16:57 ` [U-Boot] [PATCH 3/3] i2c: tegra: dump alen in debug statements Stephen Warren
2014-06-25 23:40   ` Yen Lin
2014-06-25 23:36 ` [U-Boot] [PATCH 1/3] i2c: tegra: use repeated start for reads Yen Lin
2014-06-26  2:12 ` Simon Glass
2014-06-26  4:09   ` Stephen Warren
2014-06-26  8:11 ` Joakim Tjernlund
2014-06-26 16:47   ` Stephen Warren
2014-06-26 19:11     ` Joakim Tjernlund
2014-06-26 19:18       ` Stephen Warren
2014-06-26 19:24         ` Stephen Warren
2014-06-26 20:01           ` Joakim Tjernlund
2014-06-26 22:54             ` Stephen Warren
2014-06-26 19:40         ` Joakim Tjernlund
2014-07-02 18:37 ` Stephen Warren
2014-07-03  4:34   ` Heiko Schocher [this message]
2014-07-21 15:14     ` Stephen Warren

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