drm/i915: Replace the hardcoded I915_FENCE_TIMEOUT

Expose the hardcoded timeout for unsignaled foreign fences as a Kconfig
option, primarily to allow brave systems to disable the timeout and
solely rely on correct signaling.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200509105021.12542-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/Kconfig.profile b/drivers/gpu/drm/i915/Kconfig.profile
index 0bfd276..35bbe2b 100644 (file)
--- a/drivers/gpu/drm/i915/Kconfig.profile
+++ b/drivers/gpu/drm/i915/Kconfig.profile
@@ -1,3 +1,15 @@
+config DRM_I915_FENCE_TIMEOUT
+       int "Timeout for unsignaled foreign fences (ms, jiffy granularity)"
+       default 10000 # milliseconds
+       help
+         When listening to a foreign fence, we install a supplementary timer
+         to ensure that we are always signaled and our userspace is able to
+         make forward progress. This value specifies the timeout used for an
+         unsignaled foreign fence.
+
+         May be 0 to disable the timeout, and rely on the foreign fence being
+         eventually signaled.
+
 config DRM_I915_USERFAULT_AUTOSUSPEND
        int "Runtime autosuspend delay for userspace GGTT mmaps (ms)"
        default 250 # milliseconds

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 5359c73..b0da6ea 100644 (file)
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -35,6 +35,7 @@ subdir-ccflags-y += -I$(srctree)/$(src)
 
 # core driver code
 i915-y += i915_drv.o \
+         i915_config.o \
          i915_irq.o \
          i915_getparam.o \
          i915_params.o \

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 268d65e..fb41f36 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -15815,7 +15815,7 @@ intel_prepare_plane_fb(struct drm_plane *_plane,
        if (new_plane_state->uapi.fence) { /* explicit fencing */
                ret = i915_sw_fence_await_dma_fence(&state->commit_ready,
                                                    new_plane_state->uapi.fence,
-                                                   I915_FENCE_TIMEOUT,
+                                                   i915_fence_timeout(dev_priv),
                                                    GFP_KERNEL);
                if (ret < 0)
                        return ret;
@@ -15842,7 +15842,8 @@ intel_prepare_plane_fb(struct drm_plane *_plane,
 
                ret = i915_sw_fence_await_reservation(&state->commit_ready,
                                                      obj->base.resv, NULL,
-                                                     false, I915_FENCE_TIMEOUT,
+                                                     false,
+                                                     i915_fence_timeout(dev_priv),
                                                      GFP_KERNEL);
                if (ret < 0)
                        goto unpin_fb;

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
index 34be4c0..bc02237 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
@@ -108,7 +108,7 @@ bool i915_gem_clflush_object(struct drm_i915_gem_object *obj,
        if (clflush) {
                i915_sw_fence_await_reservation(&clflush->base.chain,
                                                obj->base.resv, NULL, true,
-                                               I915_FENCE_TIMEOUT,
+                                               i915_fence_timeout(to_i915(obj->base.dev)),
                                                I915_FENCE_GFP);
                dma_resv_add_excl_fence(obj->base.resv, &clflush->base.dma);
                dma_fence_work_commit(&clflush->base);

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_client_blt.c b/drivers/gpu/drm/i915/gem/i915_gem_client_blt.c
index 3a146aa..d3a86a4 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_client_blt.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_client_blt.c
@@ -288,8 +288,7 @@ int i915_gem_schedule_fill_pages_blt(struct drm_i915_gem_object *obj,
 
        i915_gem_object_lock(obj);
        err = i915_sw_fence_await_reservation(&work->wait,
-                                             obj->base.resv, NULL,
-                                             true, I915_FENCE_TIMEOUT,
+                                             obj->base.resv, NULL, true, 0,
                                              I915_FENCE_GFP);
        if (err < 0) {
                dma_fence_set_error(&work->dma, err);

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_fence.c b/drivers/gpu/drm/i915/gem/i915_gem_fence.c
index 2f6100e..8ab842c 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_fence.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_fence.c
@@ -72,8 +72,8 @@ i915_gem_object_lock_fence(struct drm_i915_gem_object *obj)
                       0, 0);
 
        if (i915_sw_fence_await_reservation(&stub->chain,
-                                           obj->base.resv, NULL,
-                                           true, I915_FENCE_TIMEOUT,
+                                           obj->base.resv, NULL, true,
+                                           i915_fence_timeout(to_i915(obj->base.dev)),
                                            I915_FENCE_GFP) < 0)
                goto err;
 

diff --git a/drivers/gpu/drm/i915/i915_config.c b/drivers/gpu/drm/i915/i915_config.c
new file mode 100644 (file)
index 0000000..b79b5f6
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_config.c
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+
+#include "i915_drv.h"
+
+unsigned long
+i915_fence_context_timeout(const struct drm_i915_private *i915, u64 context)
+{
+       if (context && IS_ACTIVE(CONFIG_DRM_I915_FENCE_TIMEOUT))
+               return msecs_to_jiffies_timeout(CONFIG_DRM_I915_FENCE_TIMEOUT);
+
+       return 0;
+}

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 7af4864..99d8b10 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -614,8 +614,16 @@ struct i915_gem_mm {
 
 #define I915_IDLE_ENGINES_TIMEOUT (200) /* in ms */
 
+unsigned long i915_fence_context_timeout(const struct drm_i915_private *i915,
+                                        u64 context);
+
+static inline unsigned long
+i915_fence_timeout(const struct drm_i915_private *i915)
+{
+       return i915_fence_context_timeout(i915, U64_MAX);
+}
+
 #define I915_RESET_TIMEOUT (10 * HZ) /* 10s */
-#define I915_FENCE_TIMEOUT (10 * HZ) /* 10s */
 
 #define I915_ENGINE_DEAD_TIMEOUT  (4 * HZ)  /* Seqno, head and subunits dead */
 #define I915_SEQNO_DEAD_TIMEOUT   (12 * HZ) /* Seqno dead with active head */

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 2c0de3a..2d5b985 100644 (file)
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1098,7 +1098,8 @@ __i915_request_await_external(struct i915_request *rq, struct dma_fence *fence)
 {
        mark_external(rq);
        return i915_sw_fence_await_dma_fence(&rq->submit, fence,
-                                            fence->context ? I915_FENCE_TIMEOUT : 0,
+                                            i915_fence_context_timeout(rq->i915,
+                                                                       fence->context),
                                             I915_FENCE_GFP);
 }