Hi, On Mon, Jan 09, 2023 at 10:26:28PM +0200, Dmitry Baryshkov wrote: > Hi, > > On 09/01/2023 18:21, Laurentiu Palcu wrote: > > Hi Dmitry, > > > > It looks like there are some issues with this patchset... :/ I just > > fetched the drm-tip and, with these patches included, the "Hot plug > > detection already enabled" warning is back for i.MX DCSS. > > Could you please provide a backtrace? Sure, see below: ------------[ cut here ]------------ 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 ]--- Cheers, Laurentiu > > > > > After a short investigation, it seems that we end up calling > > drm_bridge_hpd_enable() from both drm_kms_helper_poll_init() and > > drm_fbdev_generic_setup(), hence the warning. > > > > There are drivers using the drm_bridge_connector API that also call > > drm_kms_helper_poll_init() followed by drm_fbdev_generic_setup(). So, > > they might experience the same behavior, unless I'm missing something... > > :/ > > > > Also, even if drm_fbdev_generic_setup() is not called in the driver > > initialization, the warning will still appear the first time the > > GETCONNECTOR ioctl is called, because that'll call > > drm_helper_probe_single_connector_modes() helper which will eventually > > call drm_bridge_hpd_enable(). > > > > Any idea? > > > > Cheers, > > Laurentiu > > > > On Wed, Nov 02, 2022 at 09:06:58PM +0300, Dmitry Baryshkov wrote: > > > From all the drivers using drm_bridge_connector only iMX/dcss and OMAP > > > DRM driver do a proper work of calling > > > drm_bridge_connector_en/disable_hpd() in right places. Rather than > > > teaching each and every driver how to properly handle > > > drm_bridge_connector's HPD, make that automatic. > > > > > > Add two additional drm_connector helper funcs: enable_hpd() and > > > disable_hpd(). Make drm_kms_helper_poll_* functions call them (as this > > > is the time where the drm_bridge_connector's functions are called by the > > > drivers too). > > > > > > Changes since v2: > > > - Fixed a typo in the commit message of the second patch. > > > > > > Changes since v1: > > > - Rebased on top of v6.1-rc1 > > > - Removed the drm_bridge_connector_enable_hpd() from > > > drm_bridge_connector_init() > > > - Removed extra underscore prefix from > > > drm_bridge_connector_en/disable_hpd() helpers > > > > > > Dmitry Baryshkov (7): > > > drm/poll-helper: merge drm_kms_helper_poll_disable() and _fini() > > > drm/probe-helper: enable and disable HPD on connectors > > > drm/bridge_connector: rely on drm_kms_helper_poll_* for HPD enablement > > > drm/imx/dcss: stop using drm_bridge_connector_en/disable_hpd() > > > drm/msm/hdmi: stop using drm_bridge_connector_en/disable_hpd() > > > drm/omap: stop using drm_bridge_connector_en/disable_hpd() > > > drm/bridge_connector: drop drm_bridge_connector_en/disable_hpd() > > > > > > drivers/gpu/drm/drm_bridge_connector.c | 27 +++------------- > > > drivers/gpu/drm/drm_probe_helper.c | 40 ++++++++++++++++++----- > > > drivers/gpu/drm/imx/dcss/dcss-dev.c | 4 --- > > > drivers/gpu/drm/imx/dcss/dcss-kms.c | 2 -- > > > drivers/gpu/drm/msm/hdmi/hdmi.c | 2 -- > > > drivers/gpu/drm/omapdrm/omap_drv.c | 41 ------------------------ > > > include/drm/drm_bridge_connector.h | 2 -- > > > include/drm/drm_modeset_helper_vtables.h | 22 +++++++++++++ > > > 8 files changed, 59 insertions(+), 81 deletions(-) > > > > > > -- > > > 2.35.1 > > > > > -- > With best wishes > Dmitry >