Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1276383

Re: [PATCH] spi: davinci: fix spurious i/o error

From Sekhar Nori <nsekhar@ti.com>
Newsgroups linux.kernel
Subject Re: [PATCH] spi: davinci: fix spurious i/o error
Date 2015-11-24 13:30 +0100
Message-ID <qykTn-82V-13@gated-at.bofh.it> (permalink)
References <qyjaW-6V9-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On Tuesday 24 November 2015 04:04 PM, Sekhar Nori wrote:
> davinci_spi_bufs() uses wait_for_completion_interruptible()
> without bothering to handle -ERESTARTSYS. Due to this,
> sometime, it returns prematurely when a signal is received.
> Since the return value is never checked, userspace eventually
> receives a spurious -EIO.
> 
> To fix this, use un-interruptible wait_for_completion_timeout().
> 
> Signed-off-by: Sekhar Nori <nsekhar@ti.com>
> ---
>  drivers/spi/spi-davinci.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c
> index 7d3af3eacf57..38026aa1afd7 100644
> --- a/drivers/spi/spi-davinci.c
> +++ b/drivers/spi/spi-davinci.c
> @@ -703,7 +703,10 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
>  
>  	/* Wait for the transfer to complete */
>  	if (spicfg->io_type != SPI_IO_TYPE_POLL) {
> -		wait_for_completion_interruptible(&(dspi->done));
> +		if (wait_for_completion_timeout(&dspi->done, HZ) == 0) {
> +			dev_err(&spi->dev, "spi transfer timeout\n");
> +			return -ETIMEDOUT;

Grygorii pointed out offline that this does not recover correctly in DMA
case. I will fix and send a v2.

Thanks,
Sekhar
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread


Thread

[PATCH] spi: davinci: fix spurious i/o error Sekhar Nori <nsekhar@ti.com> - 2015-11-24 11:40 +0100
  Re: [PATCH] spi: davinci: fix spurious i/o error Sekhar Nori <nsekhar@ti.com> - 2015-11-24 13:30 +0100

csiph-web