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| author | Frieder Schrempf <frieder.schrempf@kontron.de> | 2022-11-15 19:10:00 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-08 11:18:32 +0100 |
| commit | 5c55961166d44d9fc603f52fd05615a96ca093c8 (patch) | |
| tree | 3bc11cf431f77a88b2c6e1c72b86c42cbb5b7ac9 /drivers/spi | |
| parent | 35a78cb2e54d7023e5a499b42dcc20932214fbfe (diff) | |
| download | linux-stable-5c55961166d44d9fc603f52fd05615a96ca093c8.tar.gz linux-stable-5c55961166d44d9fc603f52fd05615a96ca093c8.tar.bz2 linux-stable-5c55961166d44d9fc603f52fd05615a96ca093c8.zip | |
spi: spi-imx: Fix spi_bus_clk if requested clock is higher than input clock
[ Upstream commit db2d2dc9a0b58c6faefb6b002fdbed4f0362d1a4 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-imx.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 5b6f3655c366..ec2296a4c44d 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -429,8 +429,7 @@ 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) |