Unverified Commit 6170d077 authored by Xu Yilun's avatar Xu Yilun Committed by Mark Brown
Browse files

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: default avatarXu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/1609723749-3557-1-git-send-email-yilun.xu@intel.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 6820e812

drivers/spi/spi.c

+5 −1
Original line number Diff line number Diff line
@@ -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)