Unverified Commit 810923f3 authored by Lubomir Rintel's avatar Lubomir Rintel Committed by Mark Brown
Browse files

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: default avatarLubomir Rintel <lkundrak@v3.sk>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent aa66478a

drivers/spi/spi.c

+39 −23
Original line number Diff line number Diff line
@@ -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,

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