diff options
| author | Mark Pearson <mpearson-lenovo@squebb.ca> | 2025-08-21 14:53:07 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-13 09:34:32 +0200 |
| commit | 30cd2cb1abf4c4acdb1ddb468c946f68939819fb (patch) | |
| tree | f20664d68de62cbf5a3949eaa15688423c80a5a9 | |
| parent | 5570ad1423ee60f6e972dadb63fb2e5f90a54cbe (diff) | |
usb: typec: ucsi: Handle incorrect num_connectors capability
The UCSI spec states that the num_connectors field is 7 bits, and the
8th bit is reserved and should be set to zero.
Some buggy FW has been known to set this bit, and it can lead to a
system not booting.
Flag that the FW is not behaving correctly, and auto-fix the value
so that the system boots correctly.
Found on Lenovo P1 G8 during Linux enablement program. The FW will
be fixed, but seemed worth addressing in case it hit platforms that
aren't officially Linux supported.
Signed-off-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20250821185319.2585023-1-mpearson-lenovo@squebb.ca
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/typec/ucsi/ucsi.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index 3f568f790f39..3995483a0aa0 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -1807,6 +1807,12 @@ static int ucsi_init(struct ucsi *ucsi) ret = -ENODEV; goto err_reset; } + /* Check if reserved bit set. This is out of spec but happens in buggy FW */ + if (ucsi->cap.num_connectors & 0x80) { + dev_warn(ucsi->dev, "UCSI: Invalid num_connectors %d. Likely buggy FW\n", + ucsi->cap.num_connectors); + ucsi->cap.num_connectors &= 0x7f; // clear bit and carry on + } /* Allocate the connectors. Released in ucsi_unregister() */ connector = kcalloc(ucsi->cap.num_connectors + 1, sizeof(*connector), GFP_KERNEL); |