From: Heiner Kallweit <hkallweit1@gmail.com> stable inclusion from stable-v6.6.3 commit 74ee67b1a776db627a9f6766b1a09b10dfe66528 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8LBQP Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit f78ca48a8ba9cdec96e8839351e49eec3233b177 upstream. Currently we set SMBHSTCNT_LAST_BYTE only after the host has started receiving the last byte. If we get e.g. preempted before setting SMBHSTCNT_LAST_BYTE, the host may be finished with receiving the byte before SMBHSTCNT_LAST_BYTE is set. Therefore change the code to set SMBHSTCNT_LAST_BYTE before writing SMBHSTSTS_BYTE_DONE for the byte before the last byte. Now the code is also consistent with what we do in i801_isr_byte_done(). Reported-by: Jean Delvare <jdelvare@suse.com> Closes: https://lore.kernel.org/linux-i2c/20230828152747.09444625@endymion.delvare/ Cc: stable@vger.kernel.org Acked-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- drivers/i2c/busses/i2c-i801.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 89631fdf6e2f..a87e3c15e5fc 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -681,15 +681,11 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv, return result ? priv->status : -ETIMEDOUT; } - for (i = 1; i <= len; i++) { - if (i == len && read_write == I2C_SMBUS_READ) - smbcmd |= SMBHSTCNT_LAST_BYTE; - outb_p(smbcmd, SMBHSTCNT(priv)); - - if (i == 1) - outb_p(inb(SMBHSTCNT(priv)) | SMBHSTCNT_START, - SMBHSTCNT(priv)); + if (len == 1 && read_write == I2C_SMBUS_READ) + smbcmd |= SMBHSTCNT_LAST_BYTE; + outb_p(smbcmd | SMBHSTCNT_START, SMBHSTCNT(priv)); + for (i = 1; i <= len; i++) { status = i801_wait_byte_done(priv); if (status) return status; @@ -712,9 +708,12 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv, data->block[0] = len; } - /* Retrieve/store value in SMBBLKDAT */ - if (read_write == I2C_SMBUS_READ) + if (read_write == I2C_SMBUS_READ) { data->block[i] = inb_p(SMBBLKDAT(priv)); + if (i == len - 1) + outb_p(smbcmd | SMBHSTCNT_LAST_BYTE, SMBHSTCNT(priv)); + } + if (read_write == I2C_SMBUS_WRITE && i+1 <= len) outb_p(data->block[i+1], SMBBLKDAT(priv)); -- 2.20.1