| Message ID | 1395321995-4627-1-git-send-email-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Mar 20, 2014 at 02:26:34PM +0100, Daniel Vetter wrote: > We have two calling contexts for thise function: > > - In the crtc helper code itself as part of the ->set_config > implementation. In this calling context all modeset locks are > already held, as they should. > > - In drivers not implementing fastboot before the fbdev/fbcon setup > and initialization. This has been added for all drivers in > > commit 76a39dbfb2d1bc45219839e5a95d4ceaf6ca114f > Author: Daniel Vetter <daniel.vetter@ffwll.ch> > Date: Sun Jan 20 23:12:54 2013 +0100 > > drm/fb-helper: don't disable everything in initial_config > > In this calling context we do not hold any modeset locks since the > immediately following call to initialize the fbev emulation grabs > all these locks themselves. > > - There are two exceptions to the above rule: shmob doesn't have fbdev > emulation support. I've manually checked the callchain up to the > driver load function and no kms locks are held. > > The right fix therefore is to split this helper into an internal and > external version and add the required locking to the function exported > to drivers. > > This remedies locking inconsistencies exposed by me adding locking > WARNs as part of the recent kerneldoc abi polishing done in > > commit 62ff94a5492175759546f8bc61383189d6b49122 > Author: Daniel Vetter <daniel.vetter@ffwll.ch> > Date: Thu Jan 23 22:18:47 2014 +0100 > > drm/crtc-helper: remove LOCKING from kerneldoc > > and > > commit 63951385052f7974155fa38f962f0f4e9847f90a > Author: Daniel Vetter <daniel.vetter@ffwll.ch> > Date: Thu Jan 23 15:14:15 2014 +0100 > > drm/doc: Repleace LOCKING kerneldoc sections in drm_modes.c > > v2: It helps when I actually git add the entire thing. > > Cc: Chris Wilson <chris@chris-wilson.co.uk> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> -Chris
On Thu, Mar 20, 2014 at 02:26:34PM +0100, Daniel Vetter wrote: [...] > The right fix therefore is to split this helper into an internal and > external version and add the required locking to the function exported > to drivers. > > This remedies locking inconsistencies exposed by me adding locking > WARNs as part of the recent kerneldoc abi polishing done in Tested-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index a85517854073..5d2b7a5716e6 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -278,17 +278,7 @@ drm_encoder_disable(struct drm_encoder *encoder) encoder->bridge->funcs->post_disable(encoder->bridge); } -/** - * drm_helper_disable_unused_functions - disable unused objects - * @dev: DRM device - * - * This function walks through the entire mode setting configuration of @dev. It - * will remove any crtc links of unused encoders and encoder links of - * disconnected connectors. Then it will disable all unused encoders and crtcs - * either by calling their disable callback if available or by calling their - * dpms callback with DRM_MODE_DPMS_OFF. - */ -void drm_helper_disable_unused_functions(struct drm_device *dev) +static void __drm_helper_disable_unused_functions(struct drm_device *dev) { struct drm_encoder *encoder; struct drm_connector *connector; @@ -323,6 +313,23 @@ void drm_helper_disable_unused_functions(struct drm_device *dev) } } } + +/** + * drm_helper_disable_unused_functions - disable unused objects + * @dev: DRM device + * + * This function walks through the entire mode setting configuration of @dev. It + * will remove any crtc links of unused encoders and encoder links of + * disconnected connectors. Then it will disable all unused encoders and crtcs + * either by calling their disable callback if available or by calling their + * dpms callback with DRM_MODE_DPMS_OFF. + */ +void drm_helper_disable_unused_functions(struct drm_device *dev) +{ + drm_modeset_lock_all(dev); + __drm_helper_disable_unused_functions(dev); + drm_modeset_unlock_all(dev); +} EXPORT_SYMBOL(drm_helper_disable_unused_functions); /* @@ -552,7 +559,7 @@ drm_crtc_helper_disable(struct drm_crtc *crtc) } } - drm_helper_disable_unused_functions(dev); + __drm_helper_disable_unused_functions(dev); return 0; } @@ -776,7 +783,7 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set) set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON); } } - drm_helper_disable_unused_functions(dev); + __drm_helper_disable_unused_functions(dev); } else if (fb_changed) { set->crtc->x = set->x; set->crtc->y = set->y; @@ -1009,7 +1016,7 @@ void drm_helper_resume_force_mode(struct drm_device *dev) } /* disable the unused connectors while restoring the modesetting */ - drm_helper_disable_unused_functions(dev); + __drm_helper_disable_unused_functions(dev); } EXPORT_SYMBOL(drm_helper_resume_force_mode);
We have two calling contexts for thise function: - In the crtc helper code itself as part of the ->set_config implementation. In this calling context all modeset locks are already held, as they should. - In drivers not implementing fastboot before the fbdev/fbcon setup and initialization. This has been added for all drivers in commit 76a39dbfb2d1bc45219839e5a95d4ceaf6ca114f Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Sun Jan 20 23:12:54 2013 +0100 drm/fb-helper: don't disable everything in initial_config In this calling context we do not hold any modeset locks since the immediately following call to initialize the fbev emulation grabs all these locks themselves. - There are two exceptions to the above rule: shmob doesn't have fbdev emulation support. I've manually checked the callchain up to the driver load function and no kms locks are held. The right fix therefore is to split this helper into an internal and external version and add the required locking to the function exported to drivers. This remedies locking inconsistencies exposed by me adding locking WARNs as part of the recent kerneldoc abi polishing done in commit 62ff94a5492175759546f8bc61383189d6b49122 Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Thu Jan 23 22:18:47 2014 +0100 drm/crtc-helper: remove LOCKING from kerneldoc and commit 63951385052f7974155fa38f962f0f4e9847f90a Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Thu Jan 23 15:14:15 2014 +0100 drm/doc: Repleace LOCKING kerneldoc sections in drm_modes.c v2: It helps when I actually git add the entire thing. Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> --- drivers/gpu/drm/drm_crtc_helper.c | 35 +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 14 deletions(-)