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authorFrieder Schrempf <frieder.schrempf@kontron.de>2022-11-15 21:10:00 +0300
committerMark Brown <broonie@kernel.org>2022-11-16 14:40:00 +0300
commitdb2d2dc9a0b58c6faefb6b002fdbed4f0362d1a4 (patch)
treefddc0afc5861a67c0831fe4c03f0227e76e69d96 /drivers/spi
parent0d10e90cee9eb57882b0f7e19fd699033722e226 (diff)
downloadlinux-db2d2dc9a0b58c6faefb6b002fdbed4f0362d1a4.tar.xz
spi: spi-imx: Fix spi_bus_clk if requested clock is higher than input clock
In case the requested bus clock is higher than the input clock, the correct dividers (pre = 0, post = 0) are returned from mx51_ecspi_clkdiv(), but *fres is left uninitialized and therefore contains an arbitrary value. This causes trouble for the recently introduced PIO polling feature as the value in spi_imx->spi_bus_clk is used there to calculate for which transfers to enable PIO polling. Fix this by setting *fres even if no clock dividers are in use. This issue was observed on Kontron BL i.MX8MM with an SPI peripheral clock set to 50 MHz by default and a requested SPI bus clock of 80 MHz for the SPI NOR flash. With the fix applied the debug message from mx51_ecspi_clkdiv() now prints the following: spi_imx 30820000.spi: mx51_ecspi_clkdiv: fin: 50000000, fspi: 50000000, post: 0, pre: 0 Fixes: 6fd8b8503a0d ("spi: spi-imx: Fix out-of-order CS/SCLK operation at low speeds") Fixes: 07e759387788 ("spi: spi-imx: add PIO polling support") Cc: Marc Kleine-Budde <mkl@pengutronix.de> Cc: David Jander <david@protonic.nl> Cc: Fabio Estevam <festevam@gmail.com> Cc: Mark Brown <broonie@kernel.org> Cc: Marek Vasut <marex@denx.de> Cc: stable@vger.kernel.org Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de> Tested-by: Fabio Estevam <festevam@gmail.com> Acked-by: Marek Vasut <marex@denx.de> Link: https://lore.kernel.org/r/20221115181002.2068270-1-frieder@fris.de Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-imx.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 30d82cc7300b..468ce0a2b282 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -444,8 +444,7 @@ static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx,
unsigned int pre, post;
unsigned int fin = spi_imx->spi_clk;
- if (unlikely(fspi > fin))
- return 0;
+ fspi = min(fspi, fin);
post = fls(fin) - fls(fspi);
if (fin > fspi << post)