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

From	Sekhar Nori <nsekhar@ti.com>
Newsgroups	linux.kernel
Subject	[PATCH] spi: davinci: fix spurious i/o error
Date	2015-11-24 11:40 +0100
Message-ID	<qyjaW-6V9-5@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

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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;
+		}
 	} else {
 		while (dspi->rcount > 0 || dspi->wcount > 0) {
 			errors = davinci_spi_process_events(dspi);
-- 
2.4.4.408.g16da57c

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[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

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