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

From: Sekhar Nori
Date: Tue Nov 24 2015 - 05:34:36 EST


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@xxxxxx>
---
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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