drm/i915: Ensure that while(INREG()) are bounded (v2)
Add a new macro, wait_for, to simplify the act of waiting on a register
to change state. wait_for() takes three arguments, the condition to
inspect on every loop, the maximum amount of time to wait and whether to
yield the cpu for a length of time after each check.
v2: Upgrade failure messages to DRM_ERROR on the suggestion of
Eric Anholt. We do not expect to hit these conditions as they reflect
programming errors, so if we do we want to be notified.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index cfcf854..c43176d 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -185,8 +185,9 @@
DRM_DEBUG_KMS("pch crt adpa 0x%x", adpa);
I915_WRITE(PCH_ADPA, adpa);
- while ((I915_READ(PCH_ADPA) & ADPA_CRT_HOTPLUG_FORCE_TRIGGER) != 0)
- ;
+ if (wait_for((I915_READ(PCH_ADPA) & ADPA_CRT_HOTPLUG_FORCE_TRIGGER) == 0,
+ 1000, 1))
+ DRM_ERROR("timed out waiting for FORCE_TRIGGER");
if (HAS_PCH_CPT(dev)) {
I915_WRITE(PCH_ADPA, temp);
@@ -237,17 +238,13 @@
hotplug_en |= CRT_HOTPLUG_FORCE_DETECT;
for (i = 0; i < tries ; i++) {
- unsigned long timeout;
/* turn on the FORCE_DETECT */
I915_WRITE(PORT_HOTPLUG_EN, hotplug_en);
- timeout = jiffies + msecs_to_jiffies(1000);
/* wait for FORCE_DETECT to go off */
- do {
- if (!(I915_READ(PORT_HOTPLUG_EN) &
- CRT_HOTPLUG_FORCE_DETECT))
- break;
- msleep(1);
- } while (time_after(timeout, jiffies));
+ if (wait_for((I915_READ(PORT_HOTPLUG_EN) &
+ CRT_HOTPLUG_FORCE_DETECT) == 0,
+ 1000, 1))
+ DRM_ERROR("timed out waiting for FORCE_DETECT to go off");
}
stat = I915_READ(PORT_HOTPLUG_STAT);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 1eae234..0bf683d 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1037,7 +1037,6 @@
void i8xx_disable_fbc(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
- unsigned long timeout = jiffies + msecs_to_jiffies(1);
u32 fbc_ctl;
if (!I915_HAS_FBC(dev))
@@ -1052,12 +1051,9 @@
I915_WRITE(FBC_CONTROL, fbc_ctl);
/* Wait for compressing bit to clear */
- while (I915_READ(FBC_STATUS) & FBC_STAT_COMPRESSING) {
- if (time_after(jiffies, timeout)) {
- DRM_DEBUG_DRIVER("FBC idle timed out\n");
- break;
- }
- ; /* do nothing */
+ if (wait_for((I915_READ(FBC_STATUS) & FBC_STAT_COMPRESSING) == 0, 10, 0)) {
+ DRM_DEBUG_KMS("FBC idle timed out\n");
+ return;
}
intel_wait_for_vblank(dev);
@@ -1943,7 +1939,6 @@
int trans_vsync_reg = (pipe == 0) ? TRANS_VSYNC_A : TRANS_VSYNC_B;
int trans_dpll_sel = (pipe == 0) ? 0 : 1;
u32 temp;
- int n;
u32 pipe_bpc;
temp = I915_READ(pipeconf_reg);
@@ -2134,9 +2129,8 @@
I915_WRITE(transconf_reg, temp | TRANS_ENABLE);
I915_READ(transconf_reg);
- while ((I915_READ(transconf_reg) & TRANS_STATE_ENABLE) == 0)
- ;
-
+ if (wait_for(I915_READ(transconf_reg) & TRANS_STATE_ENABLE, 10, 0))
+ DRM_ERROR("failed to enable transcoder\n");
}
intel_crtc_load_lut(crtc);
@@ -2167,20 +2161,10 @@
temp = I915_READ(pipeconf_reg);
if ((temp & PIPEACONF_ENABLE) != 0) {
I915_WRITE(pipeconf_reg, temp & ~PIPEACONF_ENABLE);
- I915_READ(pipeconf_reg);
- n = 0;
+
/* wait for cpu pipe off, pipe state */
- while ((I915_READ(pipeconf_reg) & I965_PIPECONF_ACTIVE) != 0) {
- n++;
- if (n < 60) {
- udelay(500);
- continue;
- } else {
- DRM_DEBUG_KMS("pipe %d off delay\n",
- pipe);
- break;
- }
- }
+ if (wait_for((I915_READ(pipeconf_reg) & I965_PIPECONF_ACTIVE) == 0, 50, 1))
+ DRM_ERROR("failed to turn off cpu pipe\n");
} else
DRM_DEBUG_KMS("crtc %d is disabled\n", pipe);
@@ -2241,20 +2225,10 @@
temp = I915_READ(transconf_reg);
if ((temp & TRANS_ENABLE) != 0) {
I915_WRITE(transconf_reg, temp & ~TRANS_ENABLE);
- I915_READ(transconf_reg);
- n = 0;
+
/* wait for PCH transcoder off, transcoder state */
- while ((I915_READ(transconf_reg) & TRANS_STATE_ENABLE) != 0) {
- n++;
- if (n < 60) {
- udelay(500);
- continue;
- } else {
- DRM_DEBUG_KMS("transcoder %d off "
- "delay\n", pipe);
- break;
- }
- }
+ if (wait_for((I915_READ(transconf_reg) & TRANS_STATE_ENABLE) == 0, 50, 1))
+ DRM_ERROR("failed to disable transcoder\n");
}
temp = I915_READ(transconf_reg);
@@ -5521,7 +5495,6 @@
struct drm_i915_private *dev_priv = dev->dev_private;
u32 rgvmodectl = I915_READ(MEMMODECTL);
u8 fmax, fmin, fstart, vstart;
- int i = 0;
/* 100ms RC evaluation intervals */
I915_WRITE(RCUPEI, 100000);
@@ -5565,13 +5538,8 @@
rgvmodectl |= MEMMODE_SWMODE_EN;
I915_WRITE(MEMMODECTL, rgvmodectl);
- while (I915_READ(MEMSWCTL) & MEMCTL_CMD_STS) {
- if (i++ > 100) {
- DRM_ERROR("stuck trying to change perf mode\n");
- break;
- }
- msleep(1);
- }
+ if (wait_for((I915_READ(MEMSWCTL) & MEMCTL_CMD_STS) == 0, 1, 0))
+ DRM_ERROR("stuck trying to change perf mode\n");
msleep(1);
ironlake_set_drps(dev, fstart);
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index cee5d9c..c6629bd 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -759,22 +759,18 @@
static void ironlake_edp_panel_on (struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
- unsigned long timeout = jiffies + msecs_to_jiffies(5000);
- u32 pp, pp_status;
+ u32 pp;
- pp_status = I915_READ(PCH_PP_STATUS);
- if (pp_status & PP_ON)
+ if (I915_READ(PCH_PP_STATUS) & PP_ON)
return;
pp = I915_READ(PCH_PP_CONTROL);
pp |= PANEL_UNLOCK_REGS | POWER_TARGET_ON;
I915_WRITE(PCH_PP_CONTROL, pp);
- do {
- pp_status = I915_READ(PCH_PP_STATUS);
- } while (((pp_status & PP_ON) == 0) && !time_after(jiffies, timeout));
- if (time_after(jiffies, timeout))
- DRM_DEBUG_KMS("panel on wait timed out: 0x%08x\n", pp_status);
+ if (wait_for(I915_READ(PCH_PP_STATUS) & PP_ON, 5000, 10))
+ DRM_ERROR("panel on wait timed out: 0x%08x\n",
+ I915_READ(PCH_PP_STATUS));
pp &= ~(PANEL_UNLOCK_REGS | EDP_FORCE_VDD);
I915_WRITE(PCH_PP_CONTROL, pp);
@@ -783,18 +779,15 @@
static void ironlake_edp_panel_off (struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
- unsigned long timeout = jiffies + msecs_to_jiffies(5000);
- u32 pp, pp_status;
+ u32 pp;
pp = I915_READ(PCH_PP_CONTROL);
pp &= ~POWER_TARGET_ON;
I915_WRITE(PCH_PP_CONTROL, pp);
- do {
- pp_status = I915_READ(PCH_PP_STATUS);
- } while ((pp_status & PP_ON) && !time_after(jiffies, timeout));
- if (time_after(jiffies, timeout))
- DRM_DEBUG_KMS("panel off wait timed out\n");
+ if (wait_for((I915_READ(PCH_PP_STATUS) & PP_ON) == 0, 5000, 10))
+ DRM_ERROR("panel off wait timed out: 0x%08x\n",
+ I915_READ(PCH_PP_STATUS));
/* Make sure VDD is enabled so DP AUX will work */
pp |= EDP_FORCE_VDD;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index c552b06..2a3eaaf 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -32,6 +32,20 @@
#include "drm_crtc.h"
#include "drm_crtc_helper.h"
+
+#define wait_for(COND, MS, W) ({ \
+ unsigned long timeout__ = jiffies + msecs_to_jiffies(MS); \
+ int ret__ = 0; \
+ while (! (COND)) { \
+ if (time_after(jiffies, timeout__)) { \
+ ret__ = -ETIMEDOUT; \
+ break; \
+ } \
+ if (W) msleep(W); \
+ } \
+ ret__; \
+})
+
/*
* Display related stuff
*/
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index cb5821e..b819c10 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -96,7 +96,7 @@
static void intel_lvds_set_power(struct drm_device *dev, bool on)
{
struct drm_i915_private *dev_priv = dev->dev_private;
- u32 pp_status, ctl_reg, status_reg, lvds_reg;
+ u32 ctl_reg, status_reg, lvds_reg;
if (HAS_PCH_SPLIT(dev)) {
ctl_reg = PCH_PP_CONTROL;
@@ -114,9 +114,8 @@
I915_WRITE(ctl_reg, I915_READ(ctl_reg) |
POWER_TARGET_ON);
- do {
- pp_status = I915_READ(status_reg);
- } while ((pp_status & PP_ON) == 0);
+ if (wait_for(I915_READ(status_reg) & PP_ON, 1000, 0))
+ DRM_ERROR("timed out waiting to enable LVDS pipe");
intel_lvds_set_backlight(dev, dev_priv->backlight_duty_cycle);
} else {
@@ -124,9 +123,8 @@
I915_WRITE(ctl_reg, I915_READ(ctl_reg) &
~POWER_TARGET_ON);
- do {
- pp_status = I915_READ(status_reg);
- } while (pp_status & PP_ON);
+ if (wait_for((I915_READ(status_reg) & PP_ON) == 0, 1000, 0))
+ DRM_ERROR("timed out waiting for LVDS pipe to turn off");
I915_WRITE(lvds_reg, I915_READ(lvds_reg) & ~LVDS_PORT_EN);
POSTING_READ(lvds_reg);