[PATCH 3.14 076/228] drm/radeon/pm: dont walk the crtc list before it has been initialized (v2)

Greg Kroah-Hartman
2014-06-05T00:35:39Z

From: Alex Deucher <alexdeucher@gmail.com>

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/radeon/r600_dpm.c | 35 +++++++++++++++++++----------------
drivers/gpu/drm/radeon/radeon_pm.c | 28 ++++++++++++++++------------
2 files changed, 35 insertions(+), 28 deletions(-)

--- 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 rade
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_
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;
}

--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -1384,12 +1384,14 @@ static void radeon_pm_compute_clocks_old

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++;
+ }
}
}

@@ -1456,12 +1458,14 @@ static void radeon_pm_compute_clocks_dpm
/* 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++;
+ }
}
}