From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 29 Mar 2018 23:45:19 +0100
Subject: drm/i915: Only warn for might_sleep() before a slow wait_for_register
Git-commit: 3df82dd43be4b6efde20f819d5829c8ed5e95476
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
As intel_wait_for_register_fw() may use, and if successful only use, a
busy-wait loop, the might_sleep() warning is a little over-zealous.
Restrict it to a might_sleep_if() a slow timeout is specified (and so
the caller authorises use of a usleep).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180329224519.13598-2-chris@chris-wilson.co.uk
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/intel_uncore.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1996,7 +1996,7 @@ int __intel_wait_for_register(struct drm
u32 reg_value;
int ret;
- might_sleep();
+ might_sleep_if(slow_timeout_ms);
spin_lock_irq(&dev_priv->uncore.lock);
intel_uncore_forcewake_get__locked(dev_priv, fw);
@@ -2008,7 +2008,7 @@ int __intel_wait_for_register(struct drm
intel_uncore_forcewake_put__locked(dev_priv, fw);
spin_unlock_irq(&dev_priv->uncore.lock);
- if (ret)
+ if (ret && slow_timeout_ms)
ret = __wait_for(reg_value = I915_READ_NOTRACE(reg),
(reg_value & mask) == value,
slow_timeout_ms * 1000, 10, 1000);