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Message-ID: <52F5234B.404@att.net>
Date: Fri, 07 Feb 2014 12:17:47 -0600
From: Daniel Santos <danielfsantos@....net>
To: Luis Henriques <luis.henriques@...onical.com>,
linux-kernel@...r.kernel.org, stable@...r.kernel.org,
kernel-team@...ts.ubuntu.com
CC: Daniel Santos <daniel.santos@...ox.com>,
Mark Brown <broonie@...aro.org>
Subject: Re: [PATCH 3.5 36/88] spidev: fix hang when transfer_one_message
fails
On 02/07/2014 05:22 AM, Luis Henriques wrote:
> 3.5.7.30 -stable review patch. If anyone has any objections, please let me know.
>
> ------------------
>
> From: Daniel Santos <daniel.santos@...ox.com>
>
> commit e120cc0dcf2880a4c5c0a6cb27b655600a1cfa1d upstream.
>
> This corrects a problem in spi_pump_messages() that leads to an spi
> message hanging forever when a call to transfer_one_message() fails.
> This failure occurs in my MCP2210 driver when the cs_change bit is set
> on the last transfer in a message, an operation which the hardware does
> not support.
>
> Rationale
> Since the transfer_one_message() returns an int, we must presume that it
> may fail. If transfer_one_message() should never fail, it should return
> void. Thus, calls to transfer_one_message() should properly manage a
> failure.
>
> Fixes: ffbbdd21329f3 (spi: create a message queueing infrastructure)
> Signed-off-by: Daniel Santos <daniel.santos@...ox.com>
> Signed-off-by: Mark Brown <broonie@...aro.org>
> Signed-off-by: Luis Henriques <luis.henriques@...onical.com>
> ---
> drivers/spi/spi.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index 1041cb8..40f528b 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -574,7 +574,9 @@ static void spi_pump_messages(struct kthread_work *work)
> ret = master->transfer_one_message(master, master->cur_msg);
> if (ret) {
> dev_err(&master->dev,
> - "failed to transfer one message from queue\n");
> + "failed to transfer one message from queue: %d\n", ret);
> + master->cur_msg->status = ret;
> + spi_finalize_current_message(master);
> return;
> }
> }
This isn't a good patch and is reverted by a later patch. I'm not sure
what the protocol for this is, but either skip this patch or include the
one that reverts it.
Daniel
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