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I'm not familiar with the analogix driver, maybe use a power
reference count would better then direct power on/off
analogix_dp.<br>
<br>
Does anyone has the idea to protect detect and get_modes context?<br>
<br>
I found many other connector driver also direct access register on
detect or get_modes, no problem for it?<br>
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On 2016年10月12日 18:00, Mark Yao wrote:<br>
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<blockquote
cite="mid:1476266442-29803-1-git-send-email-mark.yao@rock-chips.com"
type="cite">
<pre wrap="">The drm callback ->detect and ->get_modes seems is not power safe,
they may be called when device is power off, do register access on
detect or get_modes will cause system die.
Here is the path call ->detect before analogix_dp power on
[<ffffff800843babc>] analogix_dp_detect+0x44/0xdc
[<ffffff80083fd840>] drm_helper_probe_single_connector_modes_merge_bits+0xe8/0x41c
[<ffffff80083fdb84>] drm_helper_probe_single_connector_modes+0x10/0x18
[<ffffff8008418d24>] drm_mode_getconnector+0xf4/0x304
[<ffffff800840cff0>] drm_ioctl+0x23c/0x390
[<ffffff80081a8adc>] do_vfs_ioctl+0x4b8/0x58c
[<ffffff80081a8c10>] SyS_ioctl+0x60/0x88
Cc: Inki Dae <a class="moz-txt-link-rfc2396E" href="mailto:inki.dae@samsung.com"><inki.dae@samsung.com></a>
Cc: Sean Paul <a class="moz-txt-link-rfc2396E" href="mailto:seanpaul@chromium.org"><seanpaul@chromium.org></a>
Cc: Gustavo Padovan <a class="moz-txt-link-rfc2396E" href="mailto:gustavo.padovan@collabora.co.uk"><gustavo.padovan@collabora.co.uk></a>
Cc: "Ville Syrjälä" <a class="moz-txt-link-rfc2396E" href="mailto:ville.syrjala@linux.intel.com"><ville.syrjala@linux.intel.com></a>
Signed-off-by: Mark Yao <a class="moz-txt-link-rfc2396E" href="mailto:mark.yao@rock-chips.com"><mark.yao@rock-chips.com></a>
---
drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 28 ++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index efac8ab..09dece2 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1062,6 +1062,13 @@ int analogix_dp_get_modes(struct drm_connector *connector)
return 0;
}
+ if (dp->dpms_mode != DRM_MODE_DPMS_ON) {
+ pm_runtime_get_sync(dp->dev);
+
+ if (dp->plat_data->power_on)
+ dp->plat_data->power_on(dp->plat_data);
+ }
+
if (analogix_dp_handle_edid(dp) == 0) {
drm_mode_connector_update_edid_property(&dp->connector, edid);
num_modes += drm_add_edid_modes(&dp->connector, edid);
@@ -1073,6 +1080,13 @@ int analogix_dp_get_modes(struct drm_connector *connector)
if (dp->plat_data->get_modes)
num_modes += dp->plat_data->get_modes(dp->plat_data, connector);
+ if (dp->dpms_mode != DRM_MODE_DPMS_ON) {
+ if (dp->plat_data->power_off)
+ dp->plat_data->power_off(dp->plat_data);
+
+ pm_runtime_put_sync(dp->dev);
+ }
+
ret = analogix_dp_prepare_panel(dp, false, false);
if (ret)
DRM_ERROR("Failed to unprepare panel (%d)\n", ret);
@@ -1106,9 +1120,23 @@ analogix_dp_detect(struct drm_connector *connector, bool force)
return connector_status_disconnected;
}
+ if (dp->dpms_mode != DRM_MODE_DPMS_ON) {
+ pm_runtime_get_sync(dp->dev);
+
+ if (dp->plat_data->power_on)
+ dp->plat_data->power_on(dp->plat_data);
+ }
+
if (!analogix_dp_detect_hpd(dp))
status = connector_status_connected;
+ if (dp->dpms_mode != DRM_MODE_DPMS_ON) {
+ if (dp->plat_data->power_off)
+ dp->plat_data->power_off(dp->plat_data);
+
+ pm_runtime_put_sync(dp->dev);
+ }
+
ret = analogix_dp_prepare_panel(dp, false, false);
if (ret)
DRM_ERROR("Failed to unprepare panel (%d)\n", ret);
</pre>
</blockquote>
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<br>
<pre class="moz-signature" cols="72">--
Ｍark Yao</pre>
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