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Commit 3e03319a authored by Jonas Gorski's avatar Jonas Gorski Committed by Greg Kroah-Hartman
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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: b17de076 ("spi/bcm63xx: work around inability to keep CS up")
Signed-off-by: default avatarJonas Gorski <jonas.gorski@gmail.com>
Link: https://lore.kernel.org/r/20230629071453.62024-1-jonas.gorski@gmail.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent c9f56f3c

drivers/spi/spi-bcm63xx.c

+1 −1
Original line number Diff line number Diff line
@@ -125,7 +125,7 @@ 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