Hi Mark,
On Thu, Jan 30, 2014 at 11:38 PM, Mark Brown broonie@kernel.org wrote:
From: Mark Brown broonie@linaro.org
Don't wait indefinitely for transfers to complete but time out after 10ms more than we expect the transfer to take on the wire.
Signed-off-by: Mark Brown broonie@linaro.org
drivers/spi/spi.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 7f23cf9afa79..1826a50c2aaf 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -710,6 +710,7 @@ static int spi_transfer_one_message(struct spi_master *master, bool cur_cs = true; bool keep_cs = false; int ret = 0;
int ms = 1; spi_set_cs(msg->spi, true);@@ -727,7 +728,16 @@ static int spi_transfer_one_message(struct spi_master *master,
if (ret > 0) { ret = 0;
wait_for_completion(&master->xfer_completion);
ms = xfer->len * 8 * 1000 / xfer->speed_hz;ms += 10; /* some tolerance */ms = wait_for_completion_timeout(&master->xfer_completion,msecs_to_jiffies(ms));}if (ms == 0) {dev_err(&msg->spi->dev, "SPI transfer timed out\n");msg->status = -ETIMEDOUT; } trace_spi_transfer_stop(msg, xfer);
What if it still completes in the driver a little bit later? The driver will also call spi_finalize_current_message(), and we'll get a NULL pointer dereference as master->cur_msg is now NULL.
So I think we need a check like (whitespace damaged) below:
--- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -829,6 +829,9 @@ void spi_finalize_current_message(struct spi_master *master) queue_kthread_work(&master->kworker, &master->pump_messages); spin_unlock_irqrestore(&master->queue_lock, flags);
+ if (!mesg) + return NULL; + if (master->cur_msg_prepared && master->unprepare_message) { ret = master->unprepare_message(master, mesg); if (ret) {
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds