On 24/01/2023 10:55, Jani Nikula wrote:
On Wed, 18 Jan 2023, Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> 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@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>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
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
--
With best wishes
Dmitry
