ucsi_ccg: Check DEV_INT bit only when starting CCG4
authorSing-Han Chen <singhanc@nvidia.com>
Wed, 12 Jan 2022 09:41:43 +0000 (17:41 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 26 Jan 2022 12:41:19 +0000 (13:41 +0100)
commit825911492eb15bf8bb7fb94bc0c0421fe7a6327d
treef679db6fdd37ae95dd597ec209f2c56bfa45d68b
parent26fbe9772b8c459687930511444ce443011f86bf
ucsi_ccg: Check DEV_INT bit only when starting CCG4

CCGx clears Bit 0:Device Interrupt in the INTR_REG
if CCGx is reset successfully. However, there might
be a chance that other bits in INTR_REG are not
cleared due to internal data queued in PPM. This case
misleads the driver that CCGx reset failed.

The commit checks bit 0 in INTR_REG and ignores other
bits. The ucsi driver would reset PPM later.

Fixes: 247c554a14aa ("usb: typec: ucsi: add support for Cypress CCGx")
Cc: stable@vger.kernel.org
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Sing-Han Chen <singhanc@nvidia.com>
Signed-off-by: Wayne Chang <waynec@nvidia.com>
Link: https://lore.kernel.org/r/20220112094143.628610-1-waynec@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/typec/ucsi/ucsi_ccg.c