On Tue, Oct 30, 2018 at 11:28:24AM +0200, Jani Nikula wrote: > On Tue, 30 Oct 2018, Daniel Vetter <daniel@xxxxxxxx> wrote: > > On Mon, Oct 29, 2018 at 09:05:20PM +0100, Gerd Hoffmann wrote: > >> On Mon, Oct 29, 2018 at 07:44:28PM +0200, Jani Nikula wrote: > >> > On Mon, 29 Oct 2018, Gerd Hoffmann <kraxel@xxxxxxxxxx> wrote: > >> > > Recent qemu (latest master branch, upcoming 3.1 release) got support > >> > > for EDID data. This patch adds guest driver support. > >> > > > >> > > EDID support in qemu is not (yet) enabled by default, so please use > >> > > 'qemu -device VGA,edid=on' for testing. > >> > > >> > Any chance of making this use drm_get_edid() (requires an i2c_adapter) > >> > or at least drm_do_get_edid()? > >> > >> I'll have a look at using drm_do_get_edid(). drm_get_edid() will not > >> fly as there is no i2c adapter in the first place. > > > > Hm, not sure that makes sense. drm_do_get_edid is to handle the real-world > > flakiness of sinks (it's where all the retry logic resides), if you don't > > have a i2c_adapater (because the hw has some magic "give me an edid" > > block). For virtual hw we hopefully don't randomly drop bits on the floor > > between the guest and host. Imo totally fine as-is. > > > > E.g. we also don't feed the VBT edid through drm_do_get_edid either. > > But nowadays we do handle the debugfs EDID override and the EDID > firmware loading in drm_do_get_edid(), so using that gives you those > features. Oh, missed that. Would be good to clarify the kernel doc and mention this in e.g. both drm_add_edid_modes() and &drm_connector_helper_funcs.get_modes? And maybe make it more obvious that drm_do_get_edid is also for virtual drivers, atm the kerneldoc talks a lot about DDC and everything hw. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
