spidev: fix hang when transfer_one_message fails

From: danielfsantos
Date: Sun Jan 05 2014 - 18:45:24 EST

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.

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

Signed-off-by: Daniel Santos <daniel.santos@xxxxxxxxx>
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 98f4b77..907122e 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -735,7 +735,9 @@ static void spi_pump_messages(struct kthread_work *work)
ret = master->transfer_one_message(master, master->cur_msg);
if (ret) {
- "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);

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