spi: introduce master->handle_err() callback

This callback would be useful to handle an error that occurs in the generic
implementation of transfer_one_message(). The good candidate for this is to
drain FIFO and / or to terminate DMA transfers when timeout happened.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

2 files changed, 7 insertions, 0 deletions

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index c64a3e59fce3..31d4d9d997e2 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -851,6 +851,9 @@ out:
         if (msg->status == -EINPROGRESS)
                 msg->status = ret;
 
+        if (msg->status)
+                master->handle_err(master, msg);
+
         spi_finalize_current_message(master);
 
         return ret;
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index ed9489d893a4..4eaac3a5227b 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -294,6 +294,8 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  *                    transfer_one_message are mutually exclusive; when both
  *                    are set, the generic subsystem does not call your
  *                    transfer_one callback.
+ * @handle_err: the subsystem calls the driver to handle and error that occurs
+ *              in the generic implementation of transfer_one_message().
  * @unprepare_message: undo any work done by prepare_message().
  * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS
  *      number. Any individual value may be -ENOENT for CS lines that
@@ -448,6 +450,8 @@ struct spi_master {
         void (*set_cs)(struct spi_device *spi, bool enable);
         int (*transfer_one)(struct spi_master *master, struct spi_device *spi,
                             struct spi_transfer *transfer);
+        void (*handle_err)(struct spi_master *master,
+                           struct spi_message *message);
 
         /* gpio chip select */
         int                     *cs_gpios;