[PATCH 3.13 155/212] drm/radeon/pm: don't allow debugfs/sysfs access when PX card is off (v2)

Kamal Mostafa
2014-06-17T21:44:09Z

From: Alex Deucher <alexdeucher@gmail.com>

commit 4f2f203976964e267dc477de6648bdb3acd2b74b upstream.

When the PX card is off don't try and access it. Avoid hw access
to the card while it's off (e.g., reading back invalid temperature).

v2: be less strict

bug:
https://bugzilla.kernel.org/show_bug.cgi?id=76321

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/gpu/drm/radeon/radeon_pm.c | 42 +++++++++++++++++++++++++++++++++++++-
1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index 58b0a80..f5dc5dd 100644
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -361,6 +361,11 @@ static ssize_t radeon_set_pm_profile(struct device *dev,
struct drm_device *ddev = dev_get_drvdata(dev);
struct radeon_device *rdev = ddev->dev_private;

+ /* Can't set profile when the card is off */
+ if ((rdev->flags & RADEON_IS_PX) &&
+ (ddev->switch_power_state != DRM_SWITCH_POWER_ON))
+ return -EINVAL;
+
mutex_lock(&rdev->pm.mutex);
if (rdev->pm.pm_method == PM_METHOD_PROFILE) {
if (strncmp("default", buf, strlen("default")) == 0)
@@ -409,6 +414,13 @@ static ssize_t radeon_set_pm_method(struct device *dev,
struct drm_device *ddev = dev_get_drvdata(dev);
struct radeon_device *rdev = ddev->dev_private;

+ /* Can't set method when the card is off */
+ if ((rdev->flags & RADEON_IS_PX) &&
+ (ddev->switch_power_state != DRM_SWITCH_POWER_ON)) {
+ count = -EINVAL;
+ goto fail;
+ }
+
/* we don't support the legacy modes with dpm */
if (rdev->pm.pm_method == PM_METHOD_DPM) {
count = -EINVAL;
@@ -446,6 +458,10 @@ static ssize_t radeon_get_dpm_state(struct device *dev,
struct radeon_device *rdev = ddev->dev_private;
enum radeon_pm_state_type pm = rdev->pm.dpm.user_state;

+ if ((rdev->flags & RADEON_IS_PX) &&
+ (ddev->switch_power_state != DRM_SWITCH_POWER_ON))
+ return snprintf(buf, PAGE_SIZE, "off\n");
+
return snprintf(buf, PAGE_SIZE, "%s\n",
(pm == POWER_STATE_TYPE_BATTERY) ? "battery" :
(pm == POWER_STATE_TYPE_BALANCED) ? "balanced" : "performance");
@@ -459,6 +475,11 @@ static ssize_t radeon_set_dpm_state(struct device *dev,
struct drm_device *ddev = dev_get_drvdata(dev);
struct radeon_device *rdev = ddev->dev_private;

+ /* Can't set dpm state when the card is off */
+ if ((rdev->flags & RADEON_IS_PX) &&
+ (ddev->switch_power_state != DRM_SWITCH_POWER_ON))
+ return -EINVAL;
+
mutex_lock(&rdev->pm.mutex);
if (strncmp("battery", buf, strlen("battery")) == 0)
rdev->pm.dpm.user_state = POWER_STATE_TYPE_BATTERY;
@@ -485,6 +506,10 @@ static ssize_t radeon_get_dpm_forced_performance_level(struct device *dev,
struct radeon_device *rdev = ddev->dev_private;
enum radeon_dpm_forced_level level = rdev->pm.dpm.forced_level;

+ if ((rdev->flags & RADEON_IS_PX) &&
+ (ddev->switch_power_state != DRM_SWITCH_POWER_ON))
+ return snprintf(buf, PAGE_SIZE, "off\n");
+
return snprintf(buf, PAGE_SIZE, "%s\n",
(level == RADEON_DPM_FORCED_LEVEL_AUTO) ? "auto" :
(level == RADEON_DPM_FORCED_LEVEL_LOW) ? "low" : "high");
@@ -500,6 +525,11 @@ static ssize_t radeon_set_dpm_forced_performance_level(struct device *dev,
enum radeon_dpm_forced_level level;
int ret = 0;

+ /* Can't force performance level when the card is off */
+ if ((rdev->flags & RADEON_IS_PX) &&
+ (ddev->switch_power_state != DRM_SWITCH_POWER_ON))
+ return -EINVAL;
+
mutex_lock(&rdev->pm.mutex);
if (strncmp("low", buf, strlen("low")) == 0) {
level = RADEON_DPM_FORCED_LEVEL_LOW;
@@ -538,8 +568,14 @@ static ssize_t radeon_hwmon_show_temp(struct device *dev,
char *buf)
{
struct radeon_device *rdev = dev_get_drvdata(dev);
+ struct drm_device *ddev = rdev->ddev;
int temp;

+ /* Can't get temperature when the card is off */
+ if ((rdev->flags & RADEON_IS_PX) &&
+ (ddev->switch_power_state != DRM_SWITCH_POWER_ON))
+ return -EINVAL;
+
if (rdev->asic->pm.get_temperature)
temp = radeon_get_temperature(rdev);
else
@@ -1571,8 +1607,12 @@ static int radeon_debugfs_pm_info(struct seq_file *m, void *data)
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct drm_device *dev = node->minor->dev;
struct radeon_device *rdev = dev->dev_private;
+ struct drm_device *ddev = rdev->ddev;

- if (rdev->pm.dpm_enabled) {
+ if ((rdev->flags & RADEON_IS_PX) &&
+ (ddev->switch_power_state != DRM_SWITCH_POWER_ON)) {
+ seq_printf(m, "PX asic powered off\n");
+ } else if (rdev->pm.dpm_enabled) {
mutex_lock(&rdev->pm.mutex);
if (rdev->asic->dpm.debugfs_print_current_performance_level)
radeon_dpm_debugfs_print_current_performance_level(rdev, m);
--
1.9.1