On 2018-09-13 4:29 p.m., Ville Syrjälä wrote: > On Thu, Sep 13, 2018 at 03:50:01PM +0200, Daniel Vetter wrote: >> On Thu, Sep 13, 2018 at 04:16:21PM +0300, Ville Syrjala wrote: >>> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> >>> >>> We wish to control certain driver_features flags on a per-device basis >>> while still sharing a single drm_driver instance across all the >>> devices. To that end introduce device.driver_features. By default >>> it will be set to ~0 to not impose any limits beyond >>> driver.driver_features. Drivers can then clear specific flags >>> in the per-device bitmask to limit the capabilities of the device. >>> >>> An alternative approach would be to copy the driver_features from >>> the driver into the device in drm_dev_init(), however that would >>> require verifying that no driver is currently changing >>> driver.driver_features after drm_dev_init(). Hence the ~0 apporach >>> was easier. >>> >>> Ideally we'd also make drm_driver const but there is plenty of code >>> left that wants to mutate it (eg. various vfunc assignments). We'll >>> need to fix all that up before we can make it const. >>> >>> And while at it fix up the type of the feature flag passed to >>> drm_core_check_feature(). >>> >>> v2: Streamline the && vs. & (Chris) >>> s/int/u32/ in drm_core_check_feature() args >>> >>> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> >>> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> >> >> git grep DRIVER_ATOMIC -- drivers/gpu/drm/nouveau has a 2nd supporting >> case for this. Exactly same problem as we have here. Would be good to also >> convert that one, for a bit of OCD. > > Thanks for pointing it out. I'll cook it up and send separately after > this lands. I don't suppose you'd like to do amdgpu as well, while you're at it? :) Either way, this is awesome stuff! This patch is Reviewed-by: Michel Dänzer <michel.daenzer@xxxxxxx> -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
