This is a note to let you know that I've just added the patch titled
spi: fsi: Fix clock running too fast
to the 5.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
spi-fsi-fix-clock-running-too-fast.patch
and it can be found in the queue-5.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 40b48c6c3db9a88715fe3cba079520a9a62df647
Author: Brad Bishop <bradleyb@xxxxxxxxxxxxxxxxxx>
Date: Wed Sep 9 17:28:53 2020 -0500
spi: fsi: Fix clock running too fast
[ Upstream commit 0b546bbe9474ff23e6843916ad6d567f703b2396 ]
Use a clock divider tuned to a 200MHz FSI bus frequency (the maximum). Use
of the previous divider at 200MHz results in corrupt data from endpoint
devices. Ideally the clock divider would be calculated from the FSI clock,
but that would require some significant work on the FSI driver. With FSI
frequencies slower than 200MHz, the SPI clock will simply run slower, but
safely.
Signed-off-by: Brad Bishop <bradleyb@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxx>
Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
Link: https://lore.kernel.org/r/20200909222857.28653-3-eajames@xxxxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/spi/spi-fsi.c b/drivers/spi/spi-fsi.c
index ef5e0826a53c3..a702e9d7d68c0 100644
--- a/drivers/spi/spi-fsi.c
+++ b/drivers/spi/spi-fsi.c
@@ -403,7 +403,7 @@ static int fsi_spi_transfer_init(struct fsi_spi *ctx)
u64 status = 0ULL;
u64 wanted_clock_cfg = SPI_FSI_CLOCK_CFG_ECC_DISABLE |
SPI_FSI_CLOCK_CFG_SCK_NO_DEL |
- FIELD_PREP(SPI_FSI_CLOCK_CFG_SCK_DIV, 4);
+ FIELD_PREP(SPI_FSI_CLOCK_CFG_SCK_DIV, 19);
end = jiffies + msecs_to_jiffies(SPI_FSI_INIT_TIMEOUT_MS);
do {
