ucsi_ccg: Check DEV_INT bit only when starting CCG4

commit 825911492eb15bf8bb7fb94bc0c0421fe7a6327d upstream.

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: 247c554a14 ("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>
This commit is contained in:
Sing-Han Chen 2022-01-12 17:41:43 +08:00 committed by Greg Kroah-Hartman
parent 598a884c77
commit 3921d081c9

View File

@ -325,7 +325,7 @@ static int ucsi_ccg_init(struct ucsi_ccg *uc)
if (status < 0)
return status;
if (!data)
if (!(data & DEV_INT))
return 0;
status = ccg_write(uc, CCGX_RAB_INTR_REG, &data, sizeof(data));