target/linux/brcm2708/patches-3.10/0168-spidev-fix-hang-when-transfer_one_message-fails.patch

   1 From d02bc1f83cf08d59c159eb2e1263a3b4a2addc90 Mon Sep 17 00:00:00 2001
   2 From: Daniel Santos <daniel.santos@pobox.com>
   3 Date: Sun, 5 Jan 2014 17:39:26 -0600
   4 Subject: [PATCH 168/196] spidev: fix hang when transfer_one_message fails
   5
   6 commit e120cc0dcf2880a4c5c0a6cb27b655600a1cfa1d upstream.
   7
   8 This corrects a problem in spi_pump_messages() that leads to an spi
   9 message hanging forever when a call to transfer_one_message() fails.
  10 This failure occurs in my MCP2210 driver when the cs_change bit is set
  11 on the last transfer in a message, an operation which the hardware does
  12 not support.
  13
  14 Rationale
  15 Since the transfer_one_message() returns an int, we must presume that it
  16 may fail.  If transfer_one_message() should never fail, it should return
  17 void.  Thus, calls to transfer_one_message() should properly manage a
  18 failure.
  19
  20 Fixes: ffbbdd21329f3 (spi: create a message queueing infrastructure)
  21 Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
  22 Signed-off-by: Mark Brown <broonie@linaro.org>
  23 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  24 ---
  25  drivers/spi/spi.c | 4 +++-
  26  1 file changed, 3 insertions(+), 1 deletion(-)
  27
  28 diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
  29 index 32b7bb1..ca99ac9 100644
  30 --- a/drivers/spi/spi.c
  31 +++ b/drivers/spi/spi.c
  32 @@ -584,7 +584,9 @@ static void spi_pump_messages(struct kthread_work *work)
  33         ret = master->transfer_one_message(master, master->cur_msg);
  34         if (ret) {
  35                 dev_err(&master->dev,
  36 -                       "failed to transfer one message from queue\n");
  37 +                       "failed to transfer one message from queue: %d\n", ret);
  38 +               master->cur_msg->status = ret;
  39 +               spi_finalize_current_message(master);
  40                 return;
  41         }
  42  }
  43 --
  44 1.9.1
  45