This is a note to let you know that I've just added the patch titled
drm/i915: Fix locking for intel_enable_pipe_a()
to the 3.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-i915-fix-locking-for-intel_enable_pipe_a.patch
and it can be found in the queue-3.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 208bf9fdcd3575aa4a5d48b3e0295f7cdaf6fc44 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@xxxxxxxxxxxxxxx>
Date: Mon, 11 Aug 2014 13:15:35 +0300
Subject: drm/i915: Fix locking for intel_enable_pipe_a()
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From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@xxxxxxxxxxxxxxx>
commit 208bf9fdcd3575aa4a5d48b3e0295f7cdaf6fc44 upstream.
intel_enable_pipe_a() gets called with all the modeset locks already
held (by drm_modeset_lock_all()), so trying to grab the same
locks using another drm_modeset_acquire_ctx is going to fail miserably.
Move most of the drm_modeset_acquire_ctx handling (init/drop/fini)
out from intel_{get,release}_load_detect_pipe() into the callers
(intel_{crt,tv}_detect()). Only the actual locking and backoff
handling is left in intel_get_load_detect_pipe(). And in
intel_enable_pipe_a() we just share the mode_config.acquire_ctx from
drm_modeset_lock_all() which is already holding all the relevant locks.
It's perfectly legal to lock the same ww_mutex multiple times using the
same ww_acquire_ctx. drm_modeset_lock() will convert the returned
-EALREADY into 0, so the caller doesn't need to do antyhing special.
Fixes a hang on resume on my 830.
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_crt.c | 7 ++++++-
drivers/gpu/drm/i915/intel_display.c | 21 ++++-----------------
drivers/gpu/drm/i915/intel_drv.h | 3 +--
drivers/gpu/drm/i915/intel_tv.c | 7 ++++++-
4 files changed, 17 insertions(+), 21 deletions(-)
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -673,16 +673,21 @@ intel_crt_detect(struct drm_connector *c
goto out;
}
+ drm_modeset_acquire_init(&ctx, 0);
+
/* for pre-945g platforms use load detect */
if (intel_get_load_detect_pipe(connector, NULL, &tmp, &ctx)) {
if (intel_crt_detect_ddc(connector))
status = connector_status_connected;
else
status = intel_crt_load_detect(crt);
- intel_release_load_detect_pipe(connector, &tmp, &ctx);
+ intel_release_load_detect_pipe(connector, &tmp);
} else
status = connector_status_unknown;
+ drm_modeset_drop_locks(&ctx);
+ drm_modeset_acquire_fini(&ctx);
+
out:
intel_display_power_put(dev_priv, power_domain);
intel_runtime_pm_put(dev_priv);
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8319,8 +8319,6 @@ bool intel_get_load_detect_pipe(struct d
connector->base.id, connector->name,
encoder->base.id, encoder->name);
- drm_modeset_acquire_init(ctx, 0);
-
retry:
ret = drm_modeset_lock(&config->connection_mutex, ctx);
if (ret)
@@ -8435,15 +8433,11 @@ fail_unlock:
goto retry;
}
- drm_modeset_drop_locks(ctx);
- drm_modeset_acquire_fini(ctx);
-
return false;
}
void intel_release_load_detect_pipe(struct drm_connector *connector,
- struct intel_load_detect_pipe *old,
- struct drm_modeset_acquire_ctx *ctx)
+ struct intel_load_detect_pipe *old)
{
struct intel_encoder *intel_encoder =
intel_attached_encoder(connector);
@@ -8467,17 +8461,12 @@ void intel_release_load_detect_pipe(stru
drm_framebuffer_unreference(old->release_fb);
}
- goto unlock;
return;
}
/* Switch crtc and encoder back off if necessary */
if (old->dpms_mode != DRM_MODE_DPMS_ON)
connector->funcs->dpms(connector, old->dpms_mode);
-
-unlock:
- drm_modeset_drop_locks(ctx);
- drm_modeset_acquire_fini(ctx);
}
static int i9xx_pll_refclk(struct drm_device *dev,
@@ -11846,7 +11835,7 @@ static void intel_enable_pipe_a(struct d
struct intel_connector *connector;
struct drm_connector *crt = NULL;
struct intel_load_detect_pipe load_detect_temp;
- struct drm_modeset_acquire_ctx ctx;
+ struct drm_modeset_acquire_ctx *ctx = dev->mode_config.acquire_ctx;
/* We can't just switch on the pipe A, we need to set things up with a
* proper mode and output configuration. As a gross hack, enable pipe A
@@ -11863,10 +11852,8 @@ static void intel_enable_pipe_a(struct d
if (!crt)
return;
- if (intel_get_load_detect_pipe(crt, NULL, &load_detect_temp, &ctx))
- intel_release_load_detect_pipe(crt, &load_detect_temp, &ctx);
-
-
+ if (intel_get_load_detect_pipe(crt, NULL, &load_detect_temp, ctx))
+ intel_release_load_detect_pipe(crt, &load_detect_temp);
}
static bool
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -754,8 +754,7 @@ bool intel_get_load_detect_pipe(struct d
struct intel_load_detect_pipe *old,
struct drm_modeset_acquire_ctx *ctx);
void intel_release_load_detect_pipe(struct drm_connector *connector,
- struct intel_load_detect_pipe *old,
- struct drm_modeset_acquire_ctx *ctx);
+ struct intel_load_detect_pipe *old);
int intel_pin_and_fence_fb_obj(struct drm_device *dev,
struct drm_i915_gem_object *obj,
struct intel_engine_cs *pipelined);
--- a/drivers/gpu/drm/i915/intel_tv.c
+++ b/drivers/gpu/drm/i915/intel_tv.c
@@ -1323,11 +1323,16 @@ intel_tv_detect(struct drm_connector *co
struct intel_load_detect_pipe tmp;
struct drm_modeset_acquire_ctx ctx;
+ drm_modeset_acquire_init(&ctx, 0);
+
if (intel_get_load_detect_pipe(connector, &mode, &tmp, &ctx)) {
type = intel_tv_detect_type(intel_tv, connector);
- intel_release_load_detect_pipe(connector, &tmp, &ctx);
+ intel_release_load_detect_pipe(connector, &tmp);
} else
return connector_status_unknown;
+
+ drm_modeset_drop_locks(&ctx);
+ drm_modeset_acquire_fini(&ctx);
} else
return connector->status;
Patches currently in stable-queue which might be from ville.syrjala@xxxxxxxxxxxxxxx are
queue-3.16/drm-i915-skip-load-detect-when-intel_crtc-new_enable-true.patch
queue-3.16/drm-i915-wait-for-vblank-before-enabling-the-tv-encoder.patch
queue-3.16/drm-i915-fix-lock-dropping-in-intel_tv_detect.patch
queue-3.16/drm-i915-don-t-try-to-retrain-a-dp-link-on-an-inactive-crtc.patch
queue-3.16/drm-i915-fix-locking-for-intel_enable_pipe_a.patch
queue-3.16/drm-i915-fix-plane-cursor-handling-when-runtime-suspended.patch
--
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