spi: Fix the clamping of spi->max_speed_hz

If spi->controller->max_speed_hz is zero, a non-zero spi->max_speed_hz
will be overwritten by zero. Make sure spi->controller->max_speed_hz
is not zero when clamping spi->max_speed_hz.

Put the spi->controller->max_speed_hz non-zero check higher in the if,
so that we avoid a superfluous init to zero when both spi->max_speed_hz
and spi->controller->max_speed_hz are zero.

Fixes: 9326e4f1e5 ("spi: Limit the spi device max speed to controller's max speed")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20201216092321.413262-1-tudor.ambarus@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Tudor Ambarus 2020-12-16 11:23:21 +02:00 committed by Mark Brown
parent ede090f5a4
commit 6820e812da
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@ -3378,8 +3378,9 @@ int spi_setup(struct spi_device *spi)
if (status)
return status;
if (!spi->max_speed_hz ||
spi->max_speed_hz > spi->controller->max_speed_hz)
if (spi->controller->max_speed_hz &&
(!spi->max_speed_hz ||
spi->max_speed_hz > spi->controller->max_speed_hz))
spi->max_speed_hz = spi->controller->max_speed_hz;
mutex_lock(&spi->controller->io_mutex);