diff options
| author |   Xu Yilun <yilun.xu@intel.com> | 2021-01-04 09:29:09 +0800 |
|---|---|---|
| committer |   Mark Brown <broonie@kernel.org> | 2021-01-04 14:24:58 +0000 |
| commit | 6170d077bf92c5b3dfbe1021688d3c0404f7c9e9 (patch) | |
| tree | efe9108d7ae166167454080c8d93a93cf95a23be /drivers/spi/spi.c | |
| parent | spi: Fix the clamping of spi->max_speed_hz (diff) | |
| download | linux-dev-6170d077bf92c5b3dfbe1021688d3c0404f7c9e9.tar.xz linux-dev-6170d077bf92c5b3dfbe1021688d3c0404f7c9e9.zip | |
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/spi.c')
| -rw-r--r-- | drivers/spi/spi.c | 6 |
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) |