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drm/i915: Ensure that while(INREG()) are bounded (v2)
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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>
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Chris Wilson authored and Eric Anholt committed Aug 9, 2010
1 parent dd785e3 commit 913d8d1
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Showing 5 changed files with 48 additions and 78 deletions.
17 changes: 7 additions & 10 deletions drivers/gpu/drm/i915/intel_crt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -185,8 +185,9 @@ static bool intel_ironlake_crt_detect_hotplug(struct drm_connector *connector)
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);
Expand Down Expand Up @@ -237,17 +238,13 @@ static bool intel_crt_detect_hotplug(struct drm_connector *connector)
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);
Expand Down
58 changes: 13 additions & 45 deletions drivers/gpu/drm/i915/intel_display.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1037,7 +1037,6 @@ static void i8xx_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
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))
Expand All @@ -1052,12 +1051,9 @@ void i8xx_disable_fbc(struct drm_device *dev)
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);
Expand Down Expand Up @@ -1943,7 +1939,6 @@ static void ironlake_crtc_dpms(struct drm_crtc *crtc, int mode)
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);
Expand Down Expand Up @@ -2134,9 +2129,8 @@ static void ironlake_crtc_dpms(struct drm_crtc *crtc, int mode)
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);
Expand Down Expand Up @@ -2167,20 +2161,10 @@ static void ironlake_crtc_dpms(struct drm_crtc *crtc, int mode)
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);

Expand Down Expand Up @@ -2241,20 +2225,10 @@ static void ironlake_crtc_dpms(struct drm_crtc *crtc, int mode)
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);
Expand Down Expand Up @@ -5521,7 +5495,6 @@ void ironlake_enable_drps(struct drm_device *dev)
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);
Expand Down Expand Up @@ -5565,13 +5538,8 @@ void ironlake_enable_drps(struct drm_device *dev)
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);
Expand Down
25 changes: 9 additions & 16 deletions drivers/gpu/drm/i915/intel_dp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -759,22 +759,18 @@ intel_dp_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
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);
Expand All @@ -783,18 +779,15 @@ static void ironlake_edp_panel_on (struct drm_device *dev)
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;
Expand Down
14 changes: 14 additions & 0 deletions drivers/gpu/drm/i915/intel_drv.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
*/
Expand Down
12 changes: 5 additions & 7 deletions drivers/gpu/drm/i915/intel_lvds.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -96,7 +96,7 @@ static u32 intel_lvds_get_max_backlight(struct drm_device *dev)
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;
Expand All @@ -114,19 +114,17 @@ static void intel_lvds_set_power(struct drm_device *dev, bool on)

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 {
intel_lvds_set_backlight(dev, 0);

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);
Expand Down

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