From: Gustavo Sousa Date: Fri, 8 Nov 2024 12:57:07 +0000 (-0300) Subject: drm/xe: Mimic i915 behavior for non-sleeping MMIO wait X-Git-Tag: v6.14-rc1~174^2~12^2~140 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=359d2cc1f394ed62ed01540a486e744d47674c39;p=thirdparty%2Fkernel%2Flinux.git drm/xe: Mimic i915 behavior for non-sleeping MMIO wait In upcoming display changes, we will modify the DMC wakelock MMIO waiting code to choose a non-sleeping variant implementation, because the wakelock is also taking in atomic context. While xe provides an explicit parameter (namely "atomic") to prevent xe_mmio_wait32() from sleeping, i915 does not and implements that behavior when slow_timeout_ms is zero. So, for now, let's mimic what i915 does to allow for display to use non-sleeping MMIO wait. In the future, we should come up with a better and explicit interface for this behavior in i915, at least while display code is not an independent entity with proper interfaces between xe and i915. v2: - Make the tone in comment the comment added in __intel_wait_for_register() more explanatory than a FIXME-like text. (Luca) Reviewed-by: Luca Coelho Signed-off-by: Gustavo Sousa Signed-off-by: Matt Roper Link: https://patchwork.freedesktop.org/patch/msgid/20241108130218.24125-3-gustavo.sousa@intel.com --- diff --git a/drivers/gpu/drm/xe/compat-i915-headers/intel_uncore.h b/drivers/gpu/drm/xe/compat-i915-headers/intel_uncore.h index 0382beb4035b4..686c39f320e40 100644 --- a/drivers/gpu/drm/xe/compat-i915-headers/intel_uncore.h +++ b/drivers/gpu/drm/xe/compat-i915-headers/intel_uncore.h @@ -117,10 +117,19 @@ __intel_wait_for_register(struct intel_uncore *uncore, i915_reg_t i915_reg, unsigned int slow_timeout_ms, u32 *out_value) { struct xe_reg reg = XE_REG(i915_mmio_reg_offset(i915_reg)); + bool atomic; + + /* + * Replicate the behavior from i915 here, in which sleep is not + * performed if slow_timeout_ms == 0. This is necessary because + * of some paths in display code where waits are done in atomic + * context. + */ + atomic = !slow_timeout_ms && fast_timeout_us > 0; return xe_mmio_wait32(__compat_uncore_to_mmio(uncore), reg, mask, value, fast_timeout_us + 1000 * slow_timeout_ms, - out_value, false); + out_value, atomic); } static inline u32 intel_uncore_read_fw(struct intel_uncore *uncore,