On Tue, Jan 24, 2023 at 12:45:48PM +0200, Dmitry Baryshkov wrote: > There are two flags attemting to guard connector polling: > poll_enabled and poll_running. While poll_enabled semantics is clearly > defined and fully adhered (mark that drm_kms_helper_poll_init() was > called and not finalized by the _fini() call), the poll_running flag > doesn't have such clearliness. > > This flag is used only in drm_helper_probe_single_connector_modes() to > guard calling of drm_kms_helper_poll_enable, it doesn't guard the > drm_kms_helper_poll_fini(), etc. Change it to only be set if the polling > is actually running. Tie HPD enablement to this flag. This apparently broke something in i915. I suspect polling is no longer happening correctly while the device is runtime suspended. https://gitlab.freedesktop.org/drm/intel/-/issues/8451 > > This fixes the following warning reported after merging the HPD series: > > Hot plug detection already enabled > WARNING: CPU: 2 PID: 9 at drivers/gpu/drm/drm_bridge.c:1257 drm_bridge_hpd_enable+0x94/0x9c [drm] > Modules linked in: videobuf2_memops snd_soc_simple_card snd_soc_simple_card_utils fsl_imx8_ddr_perf videobuf2_common snd_soc_imx_spdif adv7511 etnaviv imx8m_ddrc imx_dcss mc cec nwl_dsi gov > CPU: 2 PID: 9 Comm: kworker/u8:0 Not tainted 6.2.0-rc2-15208-g25b283acd578 #6 > Hardware name: NXP i.MX8MQ EVK (DT) > Workqueue: events_unbound deferred_probe_work_func > pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : drm_bridge_hpd_enable+0x94/0x9c [drm] > lr : drm_bridge_hpd_enable+0x94/0x9c [drm] > sp : ffff800009ef3740 > x29: ffff800009ef3740 x28: ffff000009331f00 x27: 0000000000001000 > x26: 0000000000000020 x25: ffff800001148ed8 x24: ffff00000a8fe000 > x23: 00000000fffffffd x22: ffff000005086348 x21: ffff800001133ee0 > x20: ffff00000550d800 x19: ffff000005086288 x18: 0000000000000006 > x17: 0000000000000000 x16: ffff8000096ef008 x15: 97ffff2891004260 > x14: 2a1403e194000000 x13: 97ffff2891004260 x12: 2a1403e194000000 > x11: 7100385f29400801 x10: 0000000000000aa0 x9 : ffff800008112744 > x8 : ffff000000250b00 x7 : 0000000000000003 x6 : 0000000000000011 > x5 : 0000000000000000 x4 : ffff0000bd986a48 x3 : 0000000000000001 > x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000000250000 > Call trace: > drm_bridge_hpd_enable+0x94/0x9c [drm] > drm_bridge_connector_enable_hpd+0x2c/0x3c [drm_kms_helper] > drm_kms_helper_poll_enable+0x94/0x10c [drm_kms_helper] > drm_helper_probe_single_connector_modes+0x1a8/0x510 [drm_kms_helper] > drm_client_modeset_probe+0x204/0x1190 [drm] > __drm_fb_helper_initial_config_and_unlock+0x5c/0x4a4 [drm_kms_helper] > drm_fb_helper_initial_config+0x54/0x6c [drm_kms_helper] > drm_fbdev_client_hotplug+0xd0/0x140 [drm_kms_helper] > drm_fbdev_generic_setup+0x90/0x154 [drm_kms_helper] > dcss_kms_attach+0x1c8/0x254 [imx_dcss] > dcss_drv_platform_probe+0x90/0xfc [imx_dcss] > platform_probe+0x70/0xcc > really_probe+0xc4/0x2e0 > __driver_probe_device+0x80/0xf0 > driver_probe_device+0xe0/0x164 > __device_attach_driver+0xc0/0x13c > bus_for_each_drv+0x84/0xe0 > __device_attach+0xa4/0x1a0 > device_initial_probe+0x1c/0x30 > bus_probe_device+0xa4/0xb0 > deferred_probe_work_func+0x90/0xd0 > process_one_work+0x200/0x474 > worker_thread+0x74/0x43c > kthread+0xfc/0x110 > ret_from_fork+0x10/0x20 > ---[ end trace 0000000000000000 ]--- > > Reported-by: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxxxx> > Fixes: c8268795c9a9 ("drm/probe-helper: enable and disable HPD on connectors") > Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> > Tested-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx> > Acked-by: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxxxx> > Tested-by: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxxxx> > Tested-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> > --- > drivers/gpu/drm/drm_probe_helper.c | 42 +++++++++++++++--------------- > 1 file changed, 21 insertions(+), 21 deletions(-) > > diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c > index ab787d71fa66..8127be134c39 100644 > --- a/drivers/gpu/drm/drm_probe_helper.c > +++ b/drivers/gpu/drm/drm_probe_helper.c > @@ -282,7 +282,8 @@ void drm_kms_helper_poll_enable(struct drm_device *dev) > bool poll = false; > unsigned long delay = DRM_OUTPUT_POLL_PERIOD; > > - if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll) > + if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll || > + dev->mode_config.poll_running) > return; > > poll = drm_kms_helper_enable_hpd(dev); > @@ -304,6 +305,8 @@ void drm_kms_helper_poll_enable(struct drm_device *dev) > > if (poll) > schedule_delayed_work(&dev->mode_config.output_poll_work, delay); > + > + dev->mode_config.poll_running = true; > } > EXPORT_SYMBOL(drm_kms_helper_poll_enable); > > @@ -592,10 +595,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector, > } > > /* Re-enable polling in case the global poll config changed. */ > - if (drm_kms_helper_poll != dev->mode_config.poll_running) > - drm_kms_helper_poll_enable(dev); > - > - dev->mode_config.poll_running = drm_kms_helper_poll; > + drm_kms_helper_poll_enable(dev); > > if (connector->status == connector_status_disconnected) { > DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n", > @@ -735,8 +735,11 @@ static void output_poll_execute(struct work_struct *work) > changed = dev->mode_config.delayed_event; > dev->mode_config.delayed_event = false; > > - if (!drm_kms_helper_poll) > + if (!drm_kms_helper_poll && dev->mode_config.poll_running) { > + drm_kms_helper_disable_hpd(dev); > + dev->mode_config.poll_running = false; > goto out; > + } > > if (!mutex_trylock(&dev->mode_config.mutex)) { > repoll = true; > @@ -833,19 +836,6 @@ bool drm_kms_helper_is_poll_worker(void) > } > EXPORT_SYMBOL(drm_kms_helper_is_poll_worker); > > -static void drm_kms_helper_poll_disable_fini(struct drm_device *dev, bool fini) > -{ > - if (!dev->mode_config.poll_enabled) > - return; > - > - if (fini) > - dev->mode_config.poll_enabled = false; > - > - drm_kms_helper_disable_hpd(dev); > - > - cancel_delayed_work_sync(&dev->mode_config.output_poll_work); > -} > - > /** > * drm_kms_helper_poll_disable - disable output polling > * @dev: drm_device > @@ -862,7 +852,12 @@ static void drm_kms_helper_poll_disable_fini(struct drm_device *dev, bool fini) > */ > void drm_kms_helper_poll_disable(struct drm_device *dev) > { > - drm_kms_helper_poll_disable_fini(dev, false); > + if (dev->mode_config.poll_running) > + drm_kms_helper_disable_hpd(dev); > + > + cancel_delayed_work_sync(&dev->mode_config.output_poll_work); > + > + dev->mode_config.poll_running = false; > } > EXPORT_SYMBOL(drm_kms_helper_poll_disable); > > @@ -900,7 +895,12 @@ EXPORT_SYMBOL(drm_kms_helper_poll_init); > */ > void drm_kms_helper_poll_fini(struct drm_device *dev) > { > - drm_kms_helper_poll_disable_fini(dev, true); > + if (!dev->mode_config.poll_enabled) > + return; > + > + drm_kms_helper_poll_disable(dev); > + > + dev->mode_config.poll_enabled = false; > } > EXPORT_SYMBOL(drm_kms_helper_poll_fini); > > -- > 2.39.0 -- Ville Syrjälä Intel
