From: Chris Wilson Date: Wed, 12 Oct 2016 09:05:18 +0000 (+0100) Subject: drm/i915: Allow disabling error capture X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=98a2f411671fe08612ff0ef977136253606a6ef7;p=openwrt%2Fstaging%2Fblogic.git drm/i915: Allow disabling error capture We currently capture the GPU state after we detect a hang. This is vital for us to both triage and debug hangs in the wild (post-mortem debugging). However, it comes at the cost of running some potentially dangerous code (since it has to make very few assumption about the state of the driver) that is quite resource intensive. This patch introduces both a method to disable error capture at runtime (for users who hit bugs at runtime and need a workaround) and to disable error capture at compiletime (for realtime users who want to minimise any possible latency, and never require error capture, saving ~30k of code). The cost is that we now have to be wary of (and test!) a kconfig flag and a module parameter. The effect of the module parameter is easy to verify through code inspection and runtime testing, but a kconfig flag needs regular compile checking. Signed-off-by: Chris Wilson Reviewed-by: Joonas Lahtinen Acked-by: Jani Nikula Acked-by: Daniel Vetter gpu_error.first_error)) return; diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index 768ad89d9cd4..629e4334719c 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -47,6 +47,7 @@ struct i915_params i915 __read_mostly = { .load_detect_test = 0, .force_reset_modeset_test = 0, .reset = true, + .error_capture = true, .invert_brightness = 0, .disable_display = 0, .enable_cmd_parser = 1, @@ -115,6 +116,14 @@ MODULE_PARM_DESC(vbt_sdvo_panel_type, module_param_named_unsafe(reset, i915.reset, bool, 0600); MODULE_PARM_DESC(reset, "Attempt GPU resets (default: true)"); +#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR) +module_param_named(error_capture, i915.error_capture, bool, 0600); +MODULE_PARM_DESC(error_capture, + "Record the GPU state following a hang. " + "This information in /sys/class/drm/card/error is vital for " + "triaging and debugging hangs."); +#endif + module_param_named_unsafe(enable_hangcheck, i915.enable_hangcheck, bool, 0644); MODULE_PARM_DESC(enable_hangcheck, "Periodically check GPU activity for detecting hangs. " diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h index 3a0dd78ddb38..94efc899c1ef 100644 --- a/drivers/gpu/drm/i915/i915_params.h +++ b/drivers/gpu/drm/i915/i915_params.h @@ -59,6 +59,7 @@ struct i915_params { bool load_detect_test; bool force_reset_modeset_test; bool reset; + bool error_capture; bool disable_display; bool verbose_state_checks; bool nuclear_pageflip; diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c index 1012eeea1324..47590ab08d7e 100644 --- a/drivers/gpu/drm/i915/i915_sysfs.c +++ b/drivers/gpu/drm/i915/i915_sysfs.c @@ -514,6 +514,8 @@ static const struct attribute *vlv_attrs[] = { NULL, }; +#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR) + static ssize_t error_state_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) @@ -571,6 +573,21 @@ static struct bin_attribute error_state_attr = { .write = error_state_write, }; +static void i915_setup_error_capture(struct device *kdev) +{ + if (sysfs_create_bin_file(&kdev->kobj, &error_state_attr)) + DRM_ERROR("error_state sysfs setup failed\n"); +} + +static void i915_teardown_error_capture(struct device *kdev) +{ + sysfs_remove_bin_file(&kdev->kobj, &error_state_attr); +} +#else +static void i915_setup_error_capture(struct device *kdev) {} +static void i915_teardown_error_capture(struct device *kdev) {} +#endif + void i915_setup_sysfs(struct drm_i915_private *dev_priv) { struct device *kdev = dev_priv->drm.primary->kdev; @@ -617,17 +634,15 @@ void i915_setup_sysfs(struct drm_i915_private *dev_priv) if (ret) DRM_ERROR("RPS sysfs setup failed\n"); - ret = sysfs_create_bin_file(&kdev->kobj, - &error_state_attr); - if (ret) - DRM_ERROR("error_state sysfs setup failed\n"); + i915_setup_error_capture(kdev); } void i915_teardown_sysfs(struct drm_i915_private *dev_priv) { struct device *kdev = dev_priv->drm.primary->kdev; - sysfs_remove_bin_file(&kdev->kobj, &error_state_attr); + i915_teardown_error_capture(kdev); + if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) sysfs_remove_files(&kdev->kobj, vlv_attrs); else diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index e4bdd3a6a6e3..cfcb03f82016 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -17097,6 +17097,8 @@ int intel_modeset_vga_set_state(struct drm_device *dev, bool state) return 0; } +#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR) + struct intel_display_error_state { u32 power_well_driver; @@ -17279,3 +17281,5 @@ intel_display_print_error_state(struct drm_i915_error_state_buf *m, err_printf(m, " VSYNC: %08x\n", error->transcoder[i].vsync); } } + +#endif diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c index a24bc8c7889f..8c411bfc3b3f 100644 --- a/drivers/gpu/drm/i915/intel_overlay.c +++ b/drivers/gpu/drm/i915/intel_overlay.c @@ -1470,6 +1470,8 @@ void intel_cleanup_overlay(struct drm_i915_private *dev_priv) kfree(dev_priv->overlay); } +#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR) + struct intel_overlay_error_state { struct overlay_registers regs; unsigned long base; @@ -1587,3 +1589,5 @@ intel_overlay_print_error_state(struct drm_i915_error_state_buf *m, P(UVSCALEV); #undef P } + +#endif