This is a note to let you know that I've just added the patch titled
spi: bcm63xx: fix max prepend length
to the 4.19-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-bcm63xx-fix-max-prepend-length.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 05d73b5b40011e55975b3dbf8e12a4af4bc43847
Author: Jonas Gorski <jonas.gorski@xxxxxxxxx>
Date: Thu Jun 29 09:14:52 2023 +0200
spi: bcm63xx: fix max prepend length
[ Upstream commit 5158814cbb37bbb38344b3ecddc24ba2ed0365f2 ]
The command word is defined as following:
/* Command */
#define SPI_CMD_COMMAND_SHIFT 0
#define SPI_CMD_DEVICE_ID_SHIFT 4
#define SPI_CMD_PREPEND_BYTE_CNT_SHIFT 8
#define SPI_CMD_ONE_BYTE_SHIFT 11
#define SPI_CMD_ONE_WIRE_SHIFT 12
If the prepend byte count field starts at bit 8, and the next defined
bit is SPI_CMD_ONE_BYTE at bit 11, it can be at most 3 bits wide, and
thus the max value is 7, not 15.
Fixes: b17de076062a ("spi/bcm63xx: work around inability to keep CS up")
Signed-off-by: Jonas Gorski <jonas.gorski@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230629071453.62024-1-jonas.gorski@xxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c
index bfe5754768f97..cc6ec3fb5bfdf 100644
--- a/drivers/spi/spi-bcm63xx.c
+++ b/drivers/spi/spi-bcm63xx.c
@@ -134,7 +134,7 @@ enum bcm63xx_regs_spi {
SPI_MSG_DATA_SIZE,
};
-#define BCM63XX_SPI_MAX_PREPEND 15
+#define BCM63XX_SPI_MAX_PREPEND 7
#define BCM63XX_SPI_MAX_CS 8
#define BCM63XX_SPI_BUS_NUM 0
