Hi Sascha, On Thu, 9 Sep 2021 07:38:22 -0400, Sasha Levin wrote: > From: Heiner Kallweit <hkallweit1@xxxxxxxxx> > > [ Upstream commit a6b8bb6a813a6621c75ceacd1fa604c0229e9624 ] > > Bit SMBHSTCNT_PEC_EN is used only if software calculates the CRC and > uses register SMBPEC. This is not supported by the driver, it supports > hw-calculation of CRC only (using bit SMBAUXSTS_CRCE). The chip spec > states the following, therefore never set bit SMBHSTCNT_PEC_EN. > > Chapter SMBus CRC Generation and Checking > If the AAC bit is set in the Auxiliary Control register, the PCH > automatically calculates and drives CRC at the end of the transmitted > packet for write cycles, and will check the CRC for read cycles. It will > not transmit the contents of the PEC register for CRC. The PEC bit must > not be set in the Host Control register. If this bit is set, unspecified > behavior will result. > > This patch is based solely on the specification and compile-tested only, > because I have no PEC-capable devices. > > Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx> > Tested-by: Jean Delvare <jdelvare@xxxxxxx> > Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- > drivers/i2c/busses/i2c-i801.c | 27 +++++++++++---------------- > 1 file changed, 11 insertions(+), 16 deletions(-) This patch fixes a theoretical problem nobody has ever complained about. I don't think it makes sense to backport it to stable kernel branches. -- Jean Delvare SUSE L3 Support
