| Message ID | 20250324132448.6134-1-johan+linaro@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | soc: qcom: pmic_glink_altmode: fix spurious DP hotplug events | expand |
On 3/24/25 06:24, Johan Hovold wrote: > The PMIC GLINK driver is currently generating DisplayPort hotplug > notifications whenever something is connected to (or disconnected from) > a port regardless of the type of notification sent by the firmware. > > These notifications are forwarded to user space by the DRM subsystem as > connector "change" uevents: > > KERNEL[1556.223776] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > ACTION=change > DEVPATH=/devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 > SUBSYSTEM=drm > HOTPLUG=1 > CONNECTOR=36 > DEVNAME=/dev/dri/card0 > DEVTYPE=drm_minor > SEQNUM=4176 > MAJOR=226 > MINOR=0 > > On the Lenovo ThinkPad X13s and T14s, the PMIC GLINK firmware sends two > identical notifications with orientation information when connecting a > charger, each generating a bogus DRM hotplug event. On the X13s, two > such notification are also sent every 90 seconds while a charger remains > connected, which again are forwarded to user space: > > port = 1, svid = ff00, mode = 255, hpd_state = 0 > payload = 01 00 00 00 00 00 00 ff 00 00 00 00 00 00 00 00 > > Note that the firmware only sends on of these when connecting an > ethernet adapter. > > Fix the spurious hotplug events by only forwarding hotplug notifications > for the Type-C DisplayPort service id. This also reduces the number of > uevents from four to two when an actual DisplayPort altmode device is > connected: > > port = 0, svid = ff01, mode = 2, hpd_state = 0 > payload = 00 01 02 00 f2 0c 01 ff 03 00 00 00 00 00 00 00 > port = 0, svid = ff01, mode = 2, hpd_state = 1 > payload = 00 01 02 00 f2 0c 01 ff 43 00 00 00 00 00 00 00 > > Fixes: 080b4e24852b ("soc: qcom: pmic_glink: Introduce altmode support") > Cc: stable@vger.kernel.org # 6.3 > Cc: Bjorn Andersson <andersson@kernel.org> > Reported-by: Clayton Craft <clayton@craftyguy.net> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > --- > > Clayton reported seeing display flickering with recent RC kernels, which > may possibly be related to these spurious events being generated with > even greater frequency. > > That still remains to be fully understood, but the spurious events, that > on the X13s are generated every 90 seconds, should be fixed either way. When a display/dock (which has ethernet) is connected, I see this hotplug change event 2 times (every 30 seconds) which I think you said this is expected now? > UDEV [236.150574] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > UDEV [236.588696] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > UDEV [266.208175] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > UDEV [266.644710] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > UDEV [296.243187] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > UDEV [296.678177] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > UDEV [326.276256] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > UDEV [326.712248] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) Not sure about you seeing it every 90s vs my 30s... anyways, I no longer see these events when a PD charger is connected though, so this patch seems to help with that! Tested-by: Clayton Craft <clayton@craftyguy.net>
On 3/24/25 2:24 PM, Johan Hovold wrote: > The PMIC GLINK driver is currently generating DisplayPort hotplug > notifications whenever something is connected to (or disconnected from) > a port regardless of the type of notification sent by the firmware. Yikes! Acked-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com> That said, I'm hoping there isn't any sort of "port is full of water, emergency" messages that we should treat as "unplug" though.. Konrad
On Mon, Mar 24, 2025 at 10:05:44AM -0700, Clayton Craft wrote: > On 3/24/25 06:24, Johan Hovold wrote: > > The PMIC GLINK driver is currently generating DisplayPort hotplug > > notifications whenever something is connected to (or disconnected from) > > a port regardless of the type of notification sent by the firmware. > > > > These notifications are forwarded to user space by the DRM subsystem as > > connector "change" uevents: > > --- > > > > Clayton reported seeing display flickering with recent RC kernels, which > > may possibly be related to these spurious events being generated with > > even greater frequency. > > > > That still remains to be fully understood, but the spurious events, that > > on the X13s are generated every 90 seconds, should be fixed either way. > > When a display/dock (which has ethernet) is connected, I see this > hotplug change event 2 times (every 30 seconds) which I think you said > this is expected now? I didn't realise you were also using a display/dock. Bjorn mentioned that he has noticed issues with one of his monitors (e.g. built-in hub reenumerating repeatedly iirc) which may be related. I see these pairs of identical notification when connecting the stock charger to one of the ports directly, and I noticed that they repeat every 90 seconds here. After plugging and unplugging a bunch of devices I think they stopped at one point, but they were there again after a reboot. So there's something going on with the PMIC GLINK firmware or driver on the X13s. I did not see these repeated messages on the T14s with just a charger (and I don't have a dock to test with). > > UDEV [236.150574] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > > UDEV [236.588696] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > > UDEV [266.208175] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > > UDEV [266.644710] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > > UDEV [296.243187] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > > UDEV [296.678177] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > > UDEV [326.276256] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > > UDEV [326.712248] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) > > Not sure about you seeing it every 90s vs my 30s... anyways, I no longer > see these events when a PD charger is connected though, so this patch > seems to help with that! Just so I understand you correctly here, you're no longer seeing the repeated uevents with this patch? Both when using a dock and when using a charger directly? Did it help with the display flickering too? Was that only on the external display? > Tested-by: Clayton Craft <clayton@craftyguy.net> Thanks for testing. Johan
On Mon, Mar 24, 2025 at 08:21:10PM +0100, Konrad Dybcio wrote: > On 3/24/25 2:24 PM, Johan Hovold wrote: > > The PMIC GLINK driver is currently generating DisplayPort hotplug > > notifications whenever something is connected to (or disconnected from) > > a port regardless of the type of notification sent by the firmware. > > Yikes! > > Acked-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com> > > That said, I'm hoping there isn't any sort of "port is full of water, > emergency" messages that we should treat as "unplug" though.. Seems a bit far fetched, but I guess only you guys inside Qualcomm can try to figure that out. An alternative could be to cache the hpd_state regardless of the svid and only forward changes. But perhaps the hpd_state bit is only valid for DP notifications. Johan
On 3/25/25 9:40 AM, Johan Hovold wrote: > On Mon, Mar 24, 2025 at 08:21:10PM +0100, Konrad Dybcio wrote: >> On 3/24/25 2:24 PM, Johan Hovold wrote: >>> The PMIC GLINK driver is currently generating DisplayPort hotplug >>> notifications whenever something is connected to (or disconnected from) >>> a port regardless of the type of notification sent by the firmware. >> >> Yikes! >> >> Acked-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com> >> >> That said, I'm hoping there isn't any sort of "port is full of water, >> emergency" messages that we should treat as "unplug" though.. > > Seems a bit far fetched, but I guess only you guys inside Qualcomm can > try to figure that out. I tried looking around, but couldn't find anything like that > An alternative could be to cache the hpd_state regardless of the svid > and only forward changes. But perhaps the hpd_state bit is only valid > for DP notifications. The current state of your patch seems to be a good approach, I think. Konrad
On Tue, Mar 25, 2025 at 09:32:10AM +0100, Johan Hovold wrote: > On Mon, Mar 24, 2025 at 10:05:44AM -0700, Clayton Craft wrote: > > On 3/24/25 06:24, Johan Hovold wrote: > > > The PMIC GLINK driver is currently generating DisplayPort hotplug > > > notifications whenever something is connected to (or disconnected from) > > > a port regardless of the type of notification sent by the firmware. > > > > > > These notifications are forwarded to user space by the DRM subsystem as > > > connector "change" uevents: > > > > --- > > > > > > Clayton reported seeing display flickering with recent RC kernels, which > > > may possibly be related to these spurious events being generated with > > > even greater frequency. > > > > > > That still remains to be fully understood, but the spurious events, that > > > on the X13s are generated every 90 seconds, should be fixed either way. > > > > When a display/dock (which has ethernet) is connected, I see this > > hotplug change event 2 times (every 30 seconds) which I think you said > > this is expected now? > > I didn't realise you were also using a display/dock. Bjorn mentioned > that he has noticed issues with one of his monitors (e.g. built-in hub > reenumerating repeatedly iirc) which may be related. > > I see these pairs of identical notification when connecting the stock > charger to one of the ports directly, and I noticed that they repeat > every 90 seconds here. After plugging and unplugging a bunch of devices > I think they stopped at one point, but they were there again after a > reboot. > > So there's something going on with the PMIC GLINK firmware or driver on > the X13s. I did not see these repeated messages on the T14s with just a > charger (and I don't have a dock to test with). With this patch enabling UCSI on sc8280xp: https://lore.kernel.org/lkml/20250326124944.6338-1-johan+linaro@kernel.org/ most of the periodic orientation notifications for the port with the charger connected appears to be gone on the X13s (note that the T14s already has UCSI enabled). I get one to three notification 90 seconds after boot with the charger connected (and two notifications when reconnecting it) but that appears to be it. Perhaps you can give that one a try with your docks and monitors as well, Clayton and Bjorn. > > Not sure about you seeing it every 90s vs my 30s... anyways, I no longer > > see these events when a PD charger is connected though, so this patch > > seems to help with that! > > Just so I understand you correctly here, you're no longer seeing the > repeated uevents with this patch? Both when using a dock and when using > a charger directly? > > Did it help with the display flickering too? Was that only on the > external display? Johan
diff --git a/drivers/soc/qcom/pmic_glink_altmode.c b/drivers/soc/qcom/pmic_glink_altmode.c index bd06ce161804..7f11acd33323 100644 --- a/drivers/soc/qcom/pmic_glink_altmode.c +++ b/drivers/soc/qcom/pmic_glink_altmode.c @@ -218,21 +218,29 @@ static void pmic_glink_altmode_worker(struct work_struct *work) { struct pmic_glink_altmode_port *alt_port = work_to_altmode_port(work); struct pmic_glink_altmode *altmode = alt_port->altmode; + enum drm_connector_status conn_status; typec_switch_set(alt_port->typec_switch, alt_port->orientation); - if (alt_port->svid == USB_TYPEC_DP_SID && alt_port->mode == 0xff) - pmic_glink_altmode_safe(altmode, alt_port); - else if (alt_port->svid == USB_TYPEC_DP_SID) - pmic_glink_altmode_enable_dp(altmode, alt_port, alt_port->mode, - alt_port->hpd_state, alt_port->hpd_irq); - else - pmic_glink_altmode_enable_usb(altmode, alt_port); + if (alt_port->svid == USB_TYPEC_DP_SID) { + if (alt_port->mode == 0xff) { + pmic_glink_altmode_safe(altmode, alt_port); + } else { + pmic_glink_altmode_enable_dp(altmode, alt_port, + alt_port->mode, + alt_port->hpd_state, + alt_port->hpd_irq); + } - drm_aux_hpd_bridge_notify(&alt_port->bridge->dev, - alt_port->hpd_state ? - connector_status_connected : - connector_status_disconnected); + if (alt_port->hpd_state) + conn_status = connector_status_connected; + else + conn_status = connector_status_disconnected; + + drm_aux_hpd_bridge_notify(&alt_port->bridge->dev, conn_status); + } else { + pmic_glink_altmode_enable_usb(altmode, alt_port); + } pmic_glink_altmode_request(altmode, ALTMODE_PAN_ACK, alt_port->index); }
The PMIC GLINK driver is currently generating DisplayPort hotplug notifications whenever something is connected to (or disconnected from) a port regardless of the type of notification sent by the firmware. These notifications are forwarded to user space by the DRM subsystem as connector "change" uevents: KERNEL[1556.223776] change /devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 (drm) ACTION=change DEVPATH=/devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0 SUBSYSTEM=drm HOTPLUG=1 CONNECTOR=36 DEVNAME=/dev/dri/card0 DEVTYPE=drm_minor SEQNUM=4176 MAJOR=226 MINOR=0 On the Lenovo ThinkPad X13s and T14s, the PMIC GLINK firmware sends two identical notifications with orientation information when connecting a charger, each generating a bogus DRM hotplug event. On the X13s, two such notification are also sent every 90 seconds while a charger remains connected, which again are forwarded to user space: port = 1, svid = ff00, mode = 255, hpd_state = 0 payload = 01 00 00 00 00 00 00 ff 00 00 00 00 00 00 00 00 Note that the firmware only sends on of these when connecting an ethernet adapter. Fix the spurious hotplug events by only forwarding hotplug notifications for the Type-C DisplayPort service id. This also reduces the number of uevents from four to two when an actual DisplayPort altmode device is connected: port = 0, svid = ff01, mode = 2, hpd_state = 0 payload = 00 01 02 00 f2 0c 01 ff 03 00 00 00 00 00 00 00 port = 0, svid = ff01, mode = 2, hpd_state = 1 payload = 00 01 02 00 f2 0c 01 ff 43 00 00 00 00 00 00 00 Fixes: 080b4e24852b ("soc: qcom: pmic_glink: Introduce altmode support") Cc: stable@vger.kernel.org # 6.3 Cc: Bjorn Andersson <andersson@kernel.org> Reported-by: Clayton Craft <clayton@craftyguy.net> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> --- Clayton reported seeing display flickering with recent RC kernels, which may possibly be related to these spurious events being generated with even greater frequency. That still remains to be fully understood, but the spurious events, that on the X13s are generated every 90 seconds, should be fixed either way. Johan drivers/soc/qcom/pmic_glink_altmode.c | 30 +++++++++++++++++---------- 1 file changed, 19 insertions(+), 11 deletions(-)