Re: [PATCH v2 2/2] i2c: at91: manage unexpected RXRDY flag when starting a transfer

Wolfram Sang
2015-10-22T13:08:55Z

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On Wed, Oct 21, 2015 at 03:44:04PM +0200, Ludovic Desroches wrote:
> In some cases, we could start a new i2c transfer with the RXRDY flag
> set. It is not a clean state and it leads to print annoying error
> messages even if there no real issue. The cause is only having garbage
> data in the Receive Holding Register because of a weird behavior of the
> RXRDY flag.
>
> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
> Fixes: 93563a6a71bb ("i2c: at91: fix a race condition when using the DMA
> controller")
> Reported-by: Peter Rosin <peda@lysator.liu.se>
> Tested-by: Peter Rosin <peda@lysator.liu.se>
> Cc: stable@vger.kernel.org #4.1

SMATCH
drivers/i2c/busses/i2c-at91.c:602 at91_do_twi_transfer warn: unused return: sr = at91_twi_read()

drivers/i2c/busses/i2c-at91.c: In function 'at91_do_twi_transfer':
drivers/i2c/busses/i2c-at91.c:550:11: warning: variable 'sr' set but not used [-Wunused-but-set-variable]
unsigned sr;
^