Re: [PATCH 3.5 36/88] spidev: fix hang when transfer_one_messagefails

From: Luis Henriques
Date: Fri Feb 07 2014 - 13:37:23 EST


On Fri, Feb 07, 2014 at 12:17:47PM -0600, Daniel Santos wrote:
> 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@xxxxxxxxx>
> >
> >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@xxxxxxxxx>
> >Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
> >Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
> >---
> > 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.

Great, thanks. I will drop this patch both in the 3.5 and 3.11
kernels.

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