From 8830f26bcd3cf1ff07d9078cd310a534c03b6a10 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 2 Nov 2018 16:12:12 +0000 Subject: drm/i915: Prevent machine hang from Broxton's vtd w/a and error capture Since capturing the error state requires fiddling around with the GGTT to read arbitrary buffers and is itself run under stop_machine(), it deadlocks the machine (effectively a hard hang) when run in conjunction with Broxton's VTd workaround to serialize GGTT access. v2: Store the ERR_PTR in first_error so that the error can be reported to the user via sysfs. v3: Mention the quirk in dmesg (using info as per usual) Fixes: 0ef34ad6222a ("drm/i915: Serialize GTT/Aperture accesses on BXT") Signed-off-by: Chris Wilson Cc: Jon Bloomfield Cc: John Harrison Cc: Tvrtko Ursulin Cc: Joonas Lahtinen Cc: Daniel Vetter Reviewed-by: Joonas Lahtinen Link: https://patchwork.freedesktop.org/patch/msgid/20181102161232.17742-5-chris@chris-wilson.co.uk (cherry picked from commit fb6f0b64e455b207a636346588e65bf9598d30eb) Signed-off-by: Joonas Lahtinen --- drivers/gpu/drm/i915/i915_gpu_error.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/i915/i915_gpu_error.h') diff --git a/drivers/gpu/drm/i915/i915_gpu_error.h b/drivers/gpu/drm/i915/i915_gpu_error.h index 8710fb18ed74..3ec89a504de5 100644 --- a/drivers/gpu/drm/i915/i915_gpu_error.h +++ b/drivers/gpu/drm/i915/i915_gpu_error.h @@ -343,6 +343,7 @@ static inline void i915_gpu_state_put(struct i915_gpu_state *gpu) struct i915_gpu_state *i915_first_error_state(struct drm_i915_private *i915); void i915_reset_error_state(struct drm_i915_private *i915); +void i915_disable_error_state(struct drm_i915_private *i915, int err); #else @@ -355,13 +356,18 @@ static inline void i915_capture_error_state(struct drm_i915_private *dev_priv, static inline struct i915_gpu_state * i915_first_error_state(struct drm_i915_private *i915) { - return NULL; + return ERR_PTR(-ENODEV); } static inline void i915_reset_error_state(struct drm_i915_private *i915) { } +static inline void i915_disable_error_state(struct drm_i915_private *i915, + int err) +{ +} + #endif /* IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR) */ #endif /* _I915_GPU_ERROR_H_ */ -- cgit v1.2.3-59-g8ed1b