spi: Deal with slaves that return from transfer_one() unfinished

Some drivers, such as spi-pxa2xx return from the transfer_one callback
immediately, idicating that the transfer will be finished asynchronously.

Normally, spi_transfer_one_message() synchronously waits for the
transfer to finish with wait_for_completion_timeout(). For slaves, we
don't want the transaction to time out as it can complete in a long time
in future. Use wait_for_completion_interruptible() instead.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 6ca5940..498d3b9 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1037,6 +1037,42 @@ static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
        return __spi_map_msg(ctlr, msg);
 }
 
+static int spi_transfer_wait(struct spi_controller *ctlr,
+                            struct spi_message *msg,
+                            struct spi_transfer *xfer)
+{
+       struct spi_statistics *statm = &ctlr->statistics;
+       struct spi_statistics *stats = &msg->spi->statistics;
+       unsigned long long ms = 1;
+
+       if (spi_controller_is_slave(ctlr)) {
+               if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
+                       dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
+                       return -EINTR;
+               }
+       } else {
+               ms = 8LL * 1000LL * xfer->len;
+               do_div(ms, xfer->speed_hz);
+               ms += ms + 200; /* some tolerance */
+
+               if (ms > UINT_MAX)
+                       ms = UINT_MAX;
+
+               ms = wait_for_completion_timeout(&ctlr->xfer_completion,
+                                                msecs_to_jiffies(ms));
+
+               if (ms == 0) {
+                       SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
+                       SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
+                       dev_err(&msg->spi->dev,
+                               "SPI transfer timed out\n");
+                       return -ETIMEDOUT;
+               }
+       }
+
+       return 0;
+}
+
 /*
  * spi_transfer_one_message - Default implementation of transfer_one_message()
  *
@@ -1050,7 +1086,6 @@ static int spi_transfer_one_message(struct spi_controller *ctlr,
        struct spi_transfer *xfer;
        bool keep_cs = false;
        int ret = 0;
-       unsigned long long ms = 1;
        struct spi_statistics *statm = &ctlr->statistics;
        struct spi_statistics *stats = &msg->spi->statistics;
 
@@ -1079,28 +1114,9 @@ static int spi_transfer_one_message(struct spi_controller *ctlr,
                                goto out;
                        }
 
-                       if (ret > 0) {
-                               ret = 0;
-                               ms = 8LL * 1000LL * xfer->len;
-                               do_div(ms, xfer->speed_hz);
-                               ms += ms + 200; /* some tolerance */
-
-                               if (ms > UINT_MAX)
-                                       ms = UINT_MAX;
-
-                               ms = wait_for_completion_timeout(&ctlr->xfer_completion,
-                                                                msecs_to_jiffies(ms));
-                       }
-
-                       if (ms == 0) {
-                               SPI_STATISTICS_INCREMENT_FIELD(statm,
-                                                              timedout);
-                               SPI_STATISTICS_INCREMENT_FIELD(stats,
-                                                              timedout);
-                               dev_err(&msg->spi->dev,
-                                       "SPI transfer timed out\n");
-                               msg->status = -ETIMEDOUT;
-                       }
+                       ret = spi_transfer_wait(ctlr, msg, xfer);
+                       if (ret < 0)
+                               msg->status = ret;
                } else {
                        if (xfer->len)
                                dev_err(&msg->spi->dev,