* [PATCH v2] drm/probe_helper: sort out poll_running vs poll_enabled
@ 2023-01-17 23:39 Dmitry Baryshkov
2023-01-18 9:02 ` Laurentiu Palcu
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Dmitry Baryshkov @ 2023-01-17 23:39 UTC (permalink / raw)
To: Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann,
David Airlie, Daniel Vetter
Cc: Neil Armstrong, intel-gfx, Chen-Yu Tsai, dri-devel,
Laurentiu Palcu, freedreno, Marek Szyprowski
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);
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);
--
2.39.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2] drm/probe_helper: sort out poll_running vs poll_enabled
2023-01-17 23:39 [PATCH v2] drm/probe_helper: sort out poll_running vs poll_enabled Dmitry Baryshkov
@ 2023-01-18 9:02 ` Laurentiu Palcu
2023-01-20 16:39 ` Laurent Pinchart
2023-01-24 8:55 ` Jani Nikula
2 siblings, 0 replies; 6+ messages in thread
From: Laurentiu Palcu @ 2023-01-18 9:02 UTC (permalink / raw)
To: Dmitry Baryshkov
Cc: Neil Armstrong, Thomas Zimmermann, freedreno, intel-gfx,
dri-devel, Chen-Yu Tsai, Marek Szyprowski
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>
I gave this a test and the warning is gone. Also, HPD works as expected.
Acked-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
Tested-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
Cheers,
Laurentiu
> ---
>
> 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);
>
> 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);
>
> --
> 2.39.0
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] drm/probe_helper: sort out poll_running vs poll_enabled
2023-01-17 23:39 [PATCH v2] drm/probe_helper: sort out poll_running vs poll_enabled Dmitry Baryshkov
2023-01-18 9:02 ` Laurentiu Palcu
@ 2023-01-20 16:39 ` Laurent Pinchart
2023-01-24 10:41 ` Dmitry Baryshkov
2023-01-24 8:55 ` Jani Nikula
2 siblings, 1 reply; 6+ messages in thread
From: Laurent Pinchart @ 2023-01-20 16:39 UTC (permalink / raw)
To: Dmitry Baryshkov
Cc: Neil Armstrong, Thomas Zimmermann, freedreno, intel-gfx,
Laurentiu Palcu, dri-devel, Chen-Yu Tsai, Marek Szyprowski
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);
>
--
Regards,
Laurent Pinchart
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] drm/probe_helper: sort out poll_running vs poll_enabled
2023-01-17 23:39 [PATCH v2] drm/probe_helper: sort out poll_running vs poll_enabled Dmitry Baryshkov
2023-01-18 9:02 ` Laurentiu Palcu
2023-01-20 16:39 ` Laurent Pinchart
@ 2023-01-24 8:55 ` Jani Nikula
2023-01-24 10:46 ` Dmitry Baryshkov
2 siblings, 1 reply; 6+ messages in thread
From: Jani Nikula @ 2023-01-24 8:55 UTC (permalink / raw)
To: Dmitry Baryshkov, Maarten Lankhorst, Maxime Ripard,
Thomas Zimmermann, David Airlie, Daniel Vetter
Cc: Neil Armstrong, intel-gfx, Chen-Yu Tsai, dri-devel,
Laurentiu Palcu, freedreno, Marek Szyprowski
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);
--
Jani Nikula, Intel Open Source Graphics Center
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] drm/probe_helper: sort out poll_running vs poll_enabled
2023-01-20 16:39 ` Laurent Pinchart
@ 2023-01-24 10:41 ` Dmitry Baryshkov
0 siblings, 0 replies; 6+ messages in thread
From: Dmitry Baryshkov @ 2023-01-24 10:41 UTC (permalink / raw)
To: Laurent Pinchart
Cc: Neil Armstrong, Thomas Zimmermann, freedreno, intel-gfx,
Laurentiu Palcu, dri-devel, Chen-Yu Tsai, Marek Szyprowski
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);
>>
>
--
With best wishes
Dmitry
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] drm/probe_helper: sort out poll_running vs poll_enabled
2023-01-24 8:55 ` Jani Nikula
@ 2023-01-24 10:46 ` Dmitry Baryshkov
0 siblings, 0 replies; 6+ messages in thread
From: Dmitry Baryshkov @ 2023-01-24 10:46 UTC (permalink / raw)
To: Jani Nikula, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann,
David Airlie, Daniel Vetter
Cc: Neil Armstrong, intel-gfx, Chen-Yu Tsai, dri-devel,
Laurentiu Palcu, freedreno, Marek Szyprowski
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
--
With best wishes
Dmitry
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-01-24 10:46 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2023-01-17 23:39 [PATCH v2] drm/probe_helper: sort out poll_running vs poll_enabled Dmitry Baryshkov
2023-01-18 9:02 ` Laurentiu Palcu
2023-01-20 16:39 ` Laurent Pinchart
2023-01-24 10:41 ` Dmitry Baryshkov
2023-01-24 8:55 ` Jani Nikula
2023-01-24 10:46 ` Dmitry Baryshkov
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