On Thu, Dec 12, 2024 at 07:37:43PM +0200, Abel Vesa wrote:
The current implementation of the ucsi glink client connector_status() callback is only relying on the state of the gpio. This means that even when the cable is unplugged, the orientation propagated to the switches along the graph is "orientation normal", instead of "orientation none", which would be the correct one in this case.
One of the Qualcomm DP-USB PHY combo drivers, which needs to be aware of the orientation change, is relying on the "orientation none" to skip the reinitialization of the entire PHY. Since the ucsi glink client advertises "orientation normal" even when the cable is unplugged, the mentioned PHY is taken down and reinitialized when in fact it should be left as-is. This triggers a crash within the displayport controller driver in turn, which brings the whole system down on some Qualcomm platforms. Propagating "orientation none" from the ucsi glink client on the connector_status() callback hides the problem of the mentioned PHY driver away for now. But the "orientation none" is nonetheless the correct one to be used in this case.
So propagate the "orientation none" instead when the connector status flags says cable is disconnected.
Fixes: 76716fd5bf09 ("usb: typec: ucsi: glink: move GPIO reading into connector_status callback") Cc: stable@vger.kernel.org # 6.10 Reviewed-by: Bryan O'Donoghue bryan.odonoghue@linaro.org Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Reviewed-by: Neil Armstrong neil.armstrong@linaro.org Signed-off-by: Abel Vesa abel.vesa@linaro.org
Changes in v2:
- Re-worded the commit message to explain a bit more what is happening.
- Added Fixes tag and CC'ed stable.
- Dropped the RFC prefix.
- Used the new UCSI_CONSTAT macro which did not exist when v1 was sent.
- Link to v1: https://lore.kernel.org/r/20241017-usb-typec-ucsi-glink-add-orientation-none...
Thanks for the update.
Reviewed-by: Johan Hovold johan+linaro@kernel.org Tested-by: Johan Hovold johan+linaro@kernel.org
Johan