[PATCH 3.12 047/146] drm/radeon/pm: don't walk the crtc list before it has been initialized (v2)

Jiri Slaby
2014-06-09T08:52:15Z

From: Alex Deucher <alexdeucher@gmail.com>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit 3ed9a335cfc64b2c83545f341cdddf2347b12b97 upstream.

Avoids a crash in certain cases when thermal irqs are generated
before the display structures have been initialized.

v2: fix the vblank and vrefresh helpers as well

bug:
https://bugzilla.kernel.org/show_bug.cgi?id=73931

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/gpu/drm/radeon/r600_dpm.c | 35 +++++++++++++++++++----------------
drivers/gpu/drm/radeon/radeon_pm.c | 28 ++++++++++++++++------------
2 files changed, 35 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/radeon/r600_dpm.c b/drivers/gpu/drm/radeon/r600_dpm.c
index 5513d8f06252..2df683aab9e9 100644
--- a/drivers/gpu/drm/radeon/r600_dpm.c
+++ b/drivers/gpu/drm/radeon/r600_dpm.c
@@ -158,16 +158,18 @@ u32 r600_dpm_get_vblank_time(struct radeon_device *rdev)
u32 line_time_us, vblank_lines;
u32 vblank_time_us = 0xffffffff; /* if the displays are off, vblank time is max */

- list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
- radeon_crtc = to_radeon_crtc(crtc);
- if (crtc->enabled && radeon_crtc->enabled && radeon_crtc->hw_mode.clock) {
- line_time_us = (radeon_crtc->hw_mode.crtc_htotal * 1000) /
- radeon_crtc->hw_mode.clock;
- vblank_lines = radeon_crtc->hw_mode.crtc_vblank_end -
- radeon_crtc->hw_mode.crtc_vdisplay +
- (radeon_crtc->v_border * 2);
- vblank_time_us = vblank_lines * line_time_us;
- break;
+ if (rdev->num_crtc && rdev->mode_info.mode_config_initialized) {
+ list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+ radeon_crtc = to_radeon_crtc(crtc);
+ if (crtc->enabled && radeon_crtc->enabled && radeon_crtc->hw_mode.clock) {
+ line_time_us = (radeon_crtc->hw_mode.crtc_htotal * 1000) /
+ radeon_crtc->hw_mode.clock;
+ vblank_lines = radeon_crtc->hw_mode.crtc_vblank_end -
+ radeon_crtc->hw_mode.crtc_vdisplay +
+ (radeon_crtc->v_border * 2);
+ vblank_time_us = vblank_lines * line_time_us;
+ break;
+ }
}
}

@@ -181,14 +183,15 @@ u32 r600_dpm_get_vrefresh(struct radeon_device *rdev)
struct radeon_crtc *radeon_crtc;
u32 vrefresh = 0;

- list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
- radeon_crtc = to_radeon_crtc(crtc);
- if (crtc->enabled && radeon_crtc->enabled && radeon_crtc->hw_mode.clock) {
- vrefresh = radeon_crtc->hw_mode.vrefresh;
- break;
+ if (rdev->num_crtc && rdev->mode_info.mode_config_initialized) {
+ list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+ radeon_crtc = to_radeon_crtc(crtc);
+ if (crtc->enabled && radeon_crtc->enabled && radeon_crtc->hw_mode.clock) {
+ vrefresh = radeon_crtc->hw_mode.vrefresh;
+ break;
+ }
}
}
-
return vrefresh;
}

diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index a0ec4bb9d896..10fc97749a81 100644
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -1362,12 +1362,14 @@ static void radeon_pm_compute_clocks_old(struct radeon_device *rdev)

rdev->pm.active_crtcs = 0;
rdev->pm.active_crtc_count = 0;
- list_for_each_entry(crtc,
- &ddev->mode_config.crtc_list, head) {
- radeon_crtc = to_radeon_crtc(crtc);
- if (radeon_crtc->enabled) {
- rdev->pm.active_crtcs |= (1 << radeon_crtc->crtc_id);
- rdev->pm.active_crtc_count++;
+ if (rdev->num_crtc && rdev->mode_info.mode_config_initialized) {
+ list_for_each_entry(crtc,
+ &ddev->mode_config.crtc_list, head) {
+ radeon_crtc = to_radeon_crtc(crtc);
+ if (radeon_crtc->enabled) {
+ rdev->pm.active_crtcs |= (1 << radeon_crtc->crtc_id);
+ rdev->pm.active_crtc_count++;
+ }
}
}

@@ -1431,12 +1433,14 @@ static void radeon_pm_compute_clocks_dpm(struct radeon_device *rdev)
/* update active crtc counts */
rdev->pm.dpm.new_active_crtcs = 0;
rdev->pm.dpm.new_active_crtc_count = 0;
- list_for_each_entry(crtc,
- &ddev->mode_config.crtc_list, head) {
- radeon_crtc = to_radeon_crtc(crtc);
- if (crtc->enabled) {
- rdev->pm.dpm.new_active_crtcs |= (1 << radeon_crtc->crtc_id);
- rdev->pm.dpm.new_active_crtc_count++;
+ if (rdev->num_crtc && rdev->mode_info.mode_config_initialized) {
+ list_for_each_entry(crtc,
+ &ddev->mode_config.crtc_list, head) {
+ radeon_crtc = to_radeon_crtc(crtc);
+ if (crtc->enabled) {
+ rdev->pm.dpm.new_active_crtcs |= (1 << radeon_crtc->crtc_id);
+ rdev->pm.dpm.new_active_crtc_count++;
+ }
}
}

--
1.9.3