Message ID | 20230117233905.1662645-1-dmitry.baryshkov@linaro.org (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | [v2] drm/probe_helper: sort out poll_running vs poll_enabled | expand |
Hi Dmitry, Thank you for the patch. On Wed, Jan 18, 2023 at 01:39:05AM +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 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@oss.nxp.com> > Fixes: c8268795c9a9 ("drm/probe-helper: enable and disable HPD on connectors") > Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> > Tested-by: Chen-Yu Tsai <wenst@chromium.org> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> This fixes the issue on my Renesas boards. Tested-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Please see below for a few comments. > --- > > Changes since v1: > - Fixed drm_kms_helper_enable_hpd() to call enable_hpd() instead of > disable_hpd(). > > --- > drivers/gpu/drm/drm_probe_helper.c | 110 +++++++++++++++++------------ > 1 file changed, 63 insertions(+), 47 deletions(-) > > diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c > index 7973f2589ced..04754bb7b131 100644 > --- a/drivers/gpu/drm/drm_probe_helper.c > +++ b/drivers/gpu/drm/drm_probe_helper.c > @@ -222,6 +222,45 @@ drm_connector_mode_valid(struct drm_connector *connector, > return ret; > } > > +static void drm_kms_helper_disable_hpd(struct drm_device *dev) > +{ > + struct drm_connector *connector; > + struct drm_connector_list_iter conn_iter; > + > + drm_connector_list_iter_begin(dev, &conn_iter); > + drm_for_each_connector_iter(connector, &conn_iter) { > + const struct drm_connector_helper_funcs *funcs = > + connector->helper_private; > + > + if (funcs && funcs->disable_hpd) > + funcs->disable_hpd(connector); > + } > + drm_connector_list_iter_end(&conn_iter); > +} > + > +static bool drm_kms_helper_enable_hpd(struct drm_device *dev) > +{ > + bool poll = false; > + struct drm_connector *connector; > + struct drm_connector_list_iter conn_iter; > + > + drm_connector_list_iter_begin(dev, &conn_iter); > + drm_for_each_connector_iter(connector, &conn_iter) { > + const struct drm_connector_helper_funcs *funcs = > + connector->helper_private; > + > + if (funcs && funcs->enable_hpd) > + funcs->enable_hpd(connector); > + > + if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | > + DRM_CONNECTOR_POLL_DISCONNECT)) > + poll = true; > + } > + drm_connector_list_iter_end(&conn_iter); > + > + return poll; > +} > + > #define DRM_OUTPUT_POLL_PERIOD (10*HZ) > /** > * drm_kms_helper_poll_enable - re-enable output polling. > @@ -241,26 +280,14 @@ drm_connector_mode_valid(struct drm_connector *connector, > void drm_kms_helper_poll_enable(struct drm_device *dev) > { > bool poll = false; > - struct drm_connector *connector; > - struct drm_connector_list_iter conn_iter; > 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) This would hold on two lines : if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll || dev->mode_config.poll_running) > return; > > - drm_connector_list_iter_begin(dev, &conn_iter); > - drm_for_each_connector_iter(connector, &conn_iter) { > - const struct drm_connector_helper_funcs *funcs = > - connector->helper_private; > - > - if (funcs && funcs->enable_hpd) > - funcs->enable_hpd(connector); > - > - if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | > - DRM_CONNECTOR_POLL_DISCONNECT)) > - poll = true; > - } > - drm_connector_list_iter_end(&conn_iter); > + poll = drm_kms_helper_enable_hpd(dev); > > if (dev->mode_config.delayed_event) { > /* > @@ -279,6 +306,8 @@ 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); > > @@ -567,10 +596,7 @@ 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", > @@ -710,8 +736,12 @@ 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) { Same here. > + drm_kms_helper_disable_hpd(dev); > + dev->mode_config.poll_running = false; > goto out; > + } > > if (!mutex_trylock(&dev->mode_config.mutex)) { > repoll = true; > @@ -808,30 +838,6 @@ 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) > -{ > - struct drm_connector *connector; > - struct drm_connector_list_iter conn_iter; > - > - if (!dev->mode_config.poll_enabled) > - return; > - > - if (fini) > - dev->mode_config.poll_enabled = false; > - > - drm_connector_list_iter_begin(dev, &conn_iter); > - drm_for_each_connector_iter(connector, &conn_iter) { > - const struct drm_connector_helper_funcs *funcs = > - connector->helper_private; > - > - if (funcs && funcs->disable_hpd) > - funcs->disable_hpd(connector); > - } > - drm_connector_list_iter_end(&conn_iter); > - > - cancel_delayed_work_sync(&dev->mode_config.output_poll_work); > -} > - > /** > * drm_kms_helper_poll_disable - disable output polling > * @dev: drm_device > @@ -848,7 +854,12 @@ 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); > > @@ -886,7 +897,12 @@ 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; The fact that poll_enabled guard init/fini and poll_running guards enable/disable is confusing :-S It would be nice if the poll_enable flag matched the enable/disable function names. One option could be - drm_kms_helper_poll_enable() -> drm_kms_helper_poll_resume() - drm_kms_helper_poll_disable() -> drm_kms_helper_poll_suspend() - drm_kms_helper_poll_init() -> drm_kms_helper_poll_enable() - drm_kms_helper_poll_fini() -> drm_kms_helper_poll_disable() This would align quite well with intended usage in drivers I think, the current enable/disable functions are documented as being used by drivers for suspend/resume, and the init()/fini() functions are documented as "init and enable" and "disable and cleanup". This isn't a candidate for this patch of course, it can be done on top. > } > EXPORT_SYMBOL(drm_kms_helper_poll_fini); >
On Wed, 18 Jan 2023, Dmitry Baryshkov <dmitry.baryshkov@linaro.org> 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 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@oss.nxp.com> > Fixes: c8268795c9a9 ("drm/probe-helper: enable and disable HPD on connectors") > Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> > Tested-by: Chen-Yu Tsai <wenst@chromium.org> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > --- > > Changes since v1: > - Fixed drm_kms_helper_enable_hpd() to call enable_hpd() instead of > disable_hpd(). > > --- > drivers/gpu/drm/drm_probe_helper.c | 110 +++++++++++++++++------------ > 1 file changed, 63 insertions(+), 47 deletions(-) > > diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c > index 7973f2589ced..04754bb7b131 100644 > --- a/drivers/gpu/drm/drm_probe_helper.c > +++ b/drivers/gpu/drm/drm_probe_helper.c > @@ -222,6 +222,45 @@ drm_connector_mode_valid(struct drm_connector *connector, > return ret; > } > > +static void drm_kms_helper_disable_hpd(struct drm_device *dev) > +{ > + struct drm_connector *connector; > + struct drm_connector_list_iter conn_iter; > + > + drm_connector_list_iter_begin(dev, &conn_iter); > + drm_for_each_connector_iter(connector, &conn_iter) { > + const struct drm_connector_helper_funcs *funcs = > + connector->helper_private; > + > + if (funcs && funcs->disable_hpd) > + funcs->disable_hpd(connector); > + } > + drm_connector_list_iter_end(&conn_iter); > +} > + > +static bool drm_kms_helper_enable_hpd(struct drm_device *dev) > +{ > + bool poll = false; > + struct drm_connector *connector; > + struct drm_connector_list_iter conn_iter; > + > + drm_connector_list_iter_begin(dev, &conn_iter); > + drm_for_each_connector_iter(connector, &conn_iter) { > + const struct drm_connector_helper_funcs *funcs = > + connector->helper_private; > + > + if (funcs && funcs->enable_hpd) > + funcs->enable_hpd(connector); > + > + if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | > + DRM_CONNECTOR_POLL_DISCONNECT)) > + poll = true; > + } > + drm_connector_list_iter_end(&conn_iter); > + > + return poll; > +} > + > #define DRM_OUTPUT_POLL_PERIOD (10*HZ) > /** > * drm_kms_helper_poll_enable - re-enable output polling. > @@ -241,26 +280,14 @@ drm_connector_mode_valid(struct drm_connector *connector, > void drm_kms_helper_poll_enable(struct drm_device *dev) > { > bool poll = false; > - struct drm_connector *connector; > - struct drm_connector_list_iter conn_iter; > 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; > > - drm_connector_list_iter_begin(dev, &conn_iter); > - drm_for_each_connector_iter(connector, &conn_iter) { > - const struct drm_connector_helper_funcs *funcs = > - connector->helper_private; > - > - if (funcs && funcs->enable_hpd) > - funcs->enable_hpd(connector); > - > - if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | > - DRM_CONNECTOR_POLL_DISCONNECT)) > - poll = true; > - } > - drm_connector_list_iter_end(&conn_iter); > + poll = drm_kms_helper_enable_hpd(dev); I'd really like to see these non-functional abstractions to functions separated from the actual functional fix. There's too much going on in the same patch here. BR, Jani. > > if (dev->mode_config.delayed_event) { > /* > @@ -279,6 +306,8 @@ 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); > > @@ -567,10 +596,7 @@ 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", > @@ -710,8 +736,12 @@ 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; > @@ -808,30 +838,6 @@ 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) > -{ > - struct drm_connector *connector; > - struct drm_connector_list_iter conn_iter; > - > - if (!dev->mode_config.poll_enabled) > - return; > - > - if (fini) > - dev->mode_config.poll_enabled = false; > - > - drm_connector_list_iter_begin(dev, &conn_iter); > - drm_for_each_connector_iter(connector, &conn_iter) { > - const struct drm_connector_helper_funcs *funcs = > - connector->helper_private; > - > - if (funcs && funcs->disable_hpd) > - funcs->disable_hpd(connector); > - } > - drm_connector_list_iter_end(&conn_iter); > - > - cancel_delayed_work_sync(&dev->mode_config.output_poll_work); > -} > - > /** > * drm_kms_helper_poll_disable - disable output polling > * @dev: drm_device > @@ -848,7 +854,12 @@ 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); > > @@ -886,7 +897,12 @@ 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);
On 20/01/2023 18:39, Laurent Pinchart wrote: > Hi Dmitry, > > Thank you for the patch. > > On Wed, Jan 18, 2023 at 01:39:05AM +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 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@oss.nxp.com> >> Fixes: c8268795c9a9 ("drm/probe-helper: enable and disable HPD on connectors") >> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> >> Tested-by: Chen-Yu Tsai <wenst@chromium.org> >> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > > This fixes the issue on my Renesas boards. > > Tested-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > > Please see below for a few comments. > [skipped two small comments, will fix them in v3] >> @@ -886,7 +897,12 @@ 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; > > The fact that poll_enabled guard init/fini and poll_running guards > enable/disable is confusing :-S It would be nice if the poll_enable flag > matched the enable/disable function names. One option could be > > - drm_kms_helper_poll_enable() -> drm_kms_helper_poll_resume() > - drm_kms_helper_poll_disable() -> drm_kms_helper_poll_suspend() > - drm_kms_helper_poll_init() -> drm_kms_helper_poll_enable() > - drm_kms_helper_poll_fini() -> drm_kms_helper_poll_disable() > > This would align quite well with intended usage in drivers I think, the > current enable/disable functions are documented as being used by drivers > for suspend/resume, and the init()/fini() functions are documented as > "init and enable" and "disable and cleanup". > > This isn't a candidate for this patch of course, it can be done on top. Yes, but I'd extremely dislike renaming a function to use the name of the function that existed previously. It can lead to very confusing issue. What do you think about keeping poll_init()/_fini() as is, reaming dev->mode_config.poll_enabled to poll_initialized, and renaming poll_enable()/disable() to suspend()/resume() as you suggested? > >> } >> EXPORT_SYMBOL(drm_kms_helper_poll_fini); >> >
On 24/01/2023 10:55, Jani Nikula wrote: > On Wed, 18 Jan 2023, Dmitry Baryshkov <dmitry.baryshkov@linaro.org> 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 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@oss.nxp.com> >> Fixes: c8268795c9a9 ("drm/probe-helper: enable and disable HPD on connectors") >> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> >> Tested-by: Chen-Yu Tsai <wenst@chromium.org> >> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> >> --- >> >> Changes since v1: >> - Fixed drm_kms_helper_enable_hpd() to call enable_hpd() instead of >> disable_hpd(). >> >> --- >> drivers/gpu/drm/drm_probe_helper.c | 110 +++++++++++++++++------------ >> 1 file changed, 63 insertions(+), 47 deletions(-) >> >> diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c >> index 7973f2589ced..04754bb7b131 100644 >> --- a/drivers/gpu/drm/drm_probe_helper.c >> +++ b/drivers/gpu/drm/drm_probe_helper.c >> @@ -222,6 +222,45 @@ drm_connector_mode_valid(struct drm_connector *connector, >> return ret; >> } >> >> +static void drm_kms_helper_disable_hpd(struct drm_device *dev) >> +{ >> + struct drm_connector *connector; >> + struct drm_connector_list_iter conn_iter; >> + >> + drm_connector_list_iter_begin(dev, &conn_iter); >> + drm_for_each_connector_iter(connector, &conn_iter) { >> + const struct drm_connector_helper_funcs *funcs = >> + connector->helper_private; >> + >> + if (funcs && funcs->disable_hpd) >> + funcs->disable_hpd(connector); >> + } >> + drm_connector_list_iter_end(&conn_iter); >> +} >> + >> +static bool drm_kms_helper_enable_hpd(struct drm_device *dev) >> +{ >> + bool poll = false; >> + struct drm_connector *connector; >> + struct drm_connector_list_iter conn_iter; >> + >> + drm_connector_list_iter_begin(dev, &conn_iter); >> + drm_for_each_connector_iter(connector, &conn_iter) { >> + const struct drm_connector_helper_funcs *funcs = >> + connector->helper_private; >> + >> + if (funcs && funcs->enable_hpd) >> + funcs->enable_hpd(connector); >> + >> + if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | >> + DRM_CONNECTOR_POLL_DISCONNECT)) >> + poll = true; >> + } >> + drm_connector_list_iter_end(&conn_iter); >> + >> + return poll; >> +} >> + >> #define DRM_OUTPUT_POLL_PERIOD (10*HZ) >> /** >> * drm_kms_helper_poll_enable - re-enable output polling. >> @@ -241,26 +280,14 @@ drm_connector_mode_valid(struct drm_connector *connector, >> void drm_kms_helper_poll_enable(struct drm_device *dev) >> { >> bool poll = false; >> - struct drm_connector *connector; >> - struct drm_connector_list_iter conn_iter; >> 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; >> >> - drm_connector_list_iter_begin(dev, &conn_iter); >> - drm_for_each_connector_iter(connector, &conn_iter) { >> - const struct drm_connector_helper_funcs *funcs = >> - connector->helper_private; >> - >> - if (funcs && funcs->enable_hpd) >> - funcs->enable_hpd(connector); >> - >> - if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | >> - DRM_CONNECTOR_POLL_DISCONNECT)) >> - poll = true; >> - } >> - drm_connector_list_iter_end(&conn_iter); >> + poll = drm_kms_helper_enable_hpd(dev); > > I'd really like to see these non-functional abstractions to functions > separated from the actual functional fix. There's too much going on in > the same patch here. Done in v3
diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 7973f2589ced..04754bb7b131 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -222,6 +222,45 @@ drm_connector_mode_valid(struct drm_connector *connector, return ret; } +static void drm_kms_helper_disable_hpd(struct drm_device *dev) +{ + struct drm_connector *connector; + struct drm_connector_list_iter conn_iter; + + drm_connector_list_iter_begin(dev, &conn_iter); + drm_for_each_connector_iter(connector, &conn_iter) { + const struct drm_connector_helper_funcs *funcs = + connector->helper_private; + + if (funcs && funcs->disable_hpd) + funcs->disable_hpd(connector); + } + drm_connector_list_iter_end(&conn_iter); +} + +static bool drm_kms_helper_enable_hpd(struct drm_device *dev) +{ + bool poll = false; + struct drm_connector *connector; + struct drm_connector_list_iter conn_iter; + + drm_connector_list_iter_begin(dev, &conn_iter); + drm_for_each_connector_iter(connector, &conn_iter) { + const struct drm_connector_helper_funcs *funcs = + connector->helper_private; + + if (funcs && funcs->enable_hpd) + funcs->enable_hpd(connector); + + if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | + DRM_CONNECTOR_POLL_DISCONNECT)) + poll = true; + } + drm_connector_list_iter_end(&conn_iter); + + return poll; +} + #define DRM_OUTPUT_POLL_PERIOD (10*HZ) /** * drm_kms_helper_poll_enable - re-enable output polling. @@ -241,26 +280,14 @@ drm_connector_mode_valid(struct drm_connector *connector, void drm_kms_helper_poll_enable(struct drm_device *dev) { bool poll = false; - struct drm_connector *connector; - struct drm_connector_list_iter conn_iter; 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; - drm_connector_list_iter_begin(dev, &conn_iter); - drm_for_each_connector_iter(connector, &conn_iter) { - const struct drm_connector_helper_funcs *funcs = - connector->helper_private; - - if (funcs && funcs->enable_hpd) - funcs->enable_hpd(connector); - - if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | - DRM_CONNECTOR_POLL_DISCONNECT)) - poll = true; - } - drm_connector_list_iter_end(&conn_iter); + poll = drm_kms_helper_enable_hpd(dev); if (dev->mode_config.delayed_event) { /* @@ -279,6 +306,8 @@ 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); @@ -567,10 +596,7 @@ 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", @@ -710,8 +736,12 @@ 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; @@ -808,30 +838,6 @@ 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) -{ - struct drm_connector *connector; - struct drm_connector_list_iter conn_iter; - - if (!dev->mode_config.poll_enabled) - return; - - if (fini) - dev->mode_config.poll_enabled = false; - - drm_connector_list_iter_begin(dev, &conn_iter); - drm_for_each_connector_iter(connector, &conn_iter) { - const struct drm_connector_helper_funcs *funcs = - connector->helper_private; - - if (funcs && funcs->disable_hpd) - funcs->disable_hpd(connector); - } - drm_connector_list_iter_end(&conn_iter); - - cancel_delayed_work_sync(&dev->mode_config.output_poll_work); -} - /** * drm_kms_helper_poll_disable - disable output polling * @dev: drm_device @@ -848,7 +854,12 @@ 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); @@ -886,7 +897,12 @@ 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);