summary refs log tree commit diff
path: root/drivers/spi
diff options
context:
space:
mode:
authorXu Yilun <yilun.xu@intel.com>2021-01-04 09:29:09 +0800
committerMark Brown <broonie@kernel.org>2021-01-04 14:24:58 +0000
commit6170d077bf92c5b3dfbe1021688d3c0404f7c9e9 (patch)
treeefe9108d7ae166167454080c8d93a93cf95a23be /drivers/spi
parent6820e812dafb4258bc14692f686eec5bde6fba86 (diff)
downloadlinux-6170d077bf92c5b3dfbe1021688d3c0404f7c9e9.tar.gz
spi: fix the divide by 0 error when calculating xfer waiting time
The xfer waiting time is the result of xfer->len / xfer->speed_hz. This
patch makes the assumption of 100khz xfer speed if the xfer->speed_hz is
not assigned and stays 0. This avoids the divide by 0 issue and ensures
a reasonable tolerant waiting time.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/1609723749-3557-1-git-send-email-yilun.xu@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index f59bf5094adb..720ab34784c1 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1108,6 +1108,7 @@ static int spi_transfer_wait(struct spi_controller *ctlr,
 {
 	struct spi_statistics *statm = &ctlr->statistics;
 	struct spi_statistics *stats = &msg->spi->statistics;
+	u32 speed_hz = xfer->speed_hz;
 	unsigned long long ms;
 
 	if (spi_controller_is_slave(ctlr)) {
@@ -1116,8 +1117,11 @@ static int spi_transfer_wait(struct spi_controller *ctlr,
 			return -EINTR;
 		}
 	} else {
+		if (!speed_hz)
+			speed_hz = 100000;
+
 		ms = 8LL * 1000LL * xfer->len;
-		do_div(ms, xfer->speed_hz);
+		do_div(ms, speed_hz);
 		ms += ms + 200; /* some tolerance */
 
 		if (ms > UINT_MAX)