This patch adds a little more control to a couple wait_for routines such that we can avoid open-coding read/wait/timeout patterns which: - need the value of the register after the wait_for - run arbitrary operation for the read portion
This patch also chooses the correct sleep function (based on timers-howto.txt) for the polling interval the caller specifies.
Changes in v2: - Added to the series Changes in v3: - Rebased on drm-intel-next-queued and the new Wmin/max _wait_for - Removed msleep option Changes in v4: - Removed ; for OP in _wait_for (Chris) - Moved reg_value definition above ret (Chris)
Suggested-by: Chris Wilson chris@chris-wilson.co.uk Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch Reviewed-by: Chris Wilson chris@chris-wilson.co.uk Signed-off-by: Sean Paul seanpaul@chromium.org --- drivers/gpu/drm/i915/intel_drv.h | 17 ++++++++++------- drivers/gpu/drm/i915/intel_uncore.c | 23 ++++++++++++++++------- drivers/gpu/drm/i915/intel_uncore.h | 14 +++++++++++++- 3 files changed, 39 insertions(+), 15 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 64426d3e078e..cbfe306cc5b7 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -41,20 +41,21 @@ #include <drm/drm_atomic.h>
/** - * _wait_for - magic (register) wait macro + * __wait_for - magic wait macro * - * Does the right thing for modeset paths when run under kdgb or similar atomic - * contexts. Note that it's important that we check the condition again after - * having timed out, since the timeout could be due to preemption or similar and - * we've never had a chance to check the condition before the timeout. + * Macro to help avoid open coding check/wait/timeout patterns. Note that it's + * important that we check the condition again after having timed out, since the + * timeout could be due to preemption or similar and we've never had a chance to + * check the condition before the timeout. */ -#define _wait_for(COND, US, Wmin, Wmax) ({ \ +#define __wait_for(OP, COND, US, Wmin, Wmax) ({ \ unsigned long timeout__ = jiffies + usecs_to_jiffies(US) + 1; \ long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \ int ret__; \ might_sleep(); \ for (;;) { \ bool expired__ = time_after(jiffies, timeout__); \ + OP; \ if (COND) { \ ret__ = 0; \ break; \ @@ -70,7 +71,9 @@ ret__; \ })
-#define wait_for(COND, MS) _wait_for((COND), (MS) * 1000, 10, 1000) +#define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \ + (Wmax)) +#define wait_for(COND, MS) _wait_for((COND), (MS) * 1000, 10, 1000)
/* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */ #if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT) diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index b4621271e7a2..2a3a77d398a0 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -1770,12 +1770,14 @@ int __intel_wait_for_register_fw(struct drm_i915_private *dev_priv, }
/** - * intel_wait_for_register - wait until register matches expected state + * __intel_wait_for_register - wait until register matches expected state * @dev_priv: the i915 device * @reg: the register to read * @mask: mask to apply to register value * @value: expected value - * @timeout_ms: timeout in millisecond + * @fast_timeout_us: fast timeout in microsecond for atomic/tight wait + * @slow_timeout_ms: slow timeout in millisecond + * @out_value: optional placeholder to hold registry value * * This routine waits until the target register @reg contains the expected * @value after applying the @mask, i.e. it waits until :: @@ -1786,14 +1788,17 @@ int __intel_wait_for_register_fw(struct drm_i915_private *dev_priv, * * Returns 0 if the register matches the desired condition, or -ETIMEOUT. */ -int intel_wait_for_register(struct drm_i915_private *dev_priv, +int __intel_wait_for_register(struct drm_i915_private *dev_priv, i915_reg_t reg, u32 mask, u32 value, - unsigned int timeout_ms) + unsigned int fast_timeout_us, + unsigned int slow_timeout_ms, + u32 *out_value) { unsigned fw = intel_uncore_forcewake_for_reg(dev_priv, reg, FW_REG_READ); + u32 reg_value; int ret;
might_sleep(); @@ -1803,14 +1808,18 @@ int intel_wait_for_register(struct drm_i915_private *dev_priv,
ret = __intel_wait_for_register_fw(dev_priv, reg, mask, value, - 2, 0, NULL); + fast_timeout_us, 0, ®_value);
intel_uncore_forcewake_put__locked(dev_priv, fw); spin_unlock_irq(&dev_priv->uncore.lock);
if (ret) - ret = wait_for((I915_READ_NOTRACE(reg) & mask) == value, - timeout_ms); + ret = __wait_for(reg_value = I915_READ_NOTRACE(reg), + (reg_value & mask) == value, + slow_timeout_ms * 1000, 10, 1000); + + if (out_value) + *out_value = reg_value;
return ret; } diff --git a/drivers/gpu/drm/i915/intel_uncore.h b/drivers/gpu/drm/i915/intel_uncore.h index 9ce079b5dd0d..bed019ef000f 100644 --- a/drivers/gpu/drm/i915/intel_uncore.h +++ b/drivers/gpu/drm/i915/intel_uncore.h @@ -163,11 +163,23 @@ void intel_uncore_forcewake_put__locked(struct drm_i915_private *dev_priv, void intel_uncore_forcewake_user_get(struct drm_i915_private *dev_priv); void intel_uncore_forcewake_user_put(struct drm_i915_private *dev_priv);
+int __intel_wait_for_register(struct drm_i915_private *dev_priv, + i915_reg_t reg, + u32 mask, + u32 value, + unsigned int fast_timeout_us, + unsigned int slow_timeout_ms, + u32 *out_value); +static inline int intel_wait_for_register(struct drm_i915_private *dev_priv, i915_reg_t reg, u32 mask, u32 value, - unsigned int timeout_ms); + unsigned int timeout_ms) +{ + return __intel_wait_for_register(dev_priv, reg, mask, value, 2, + timeout_ms, NULL); +} int __intel_wait_for_register_fw(struct drm_i915_private *dev_priv, i915_reg_t reg, u32 mask,