I briefly remember reading in some hardware doc that this actually has a defined behavior. It was something about applying either bit wise "and" or "or" on the resulting bits and returning that to the reader. This way you can check with a single broadcast read if an error occurred or if any of the instances are busy. But if you don't actually use it I suggest to not implement this. Regards, Christian. Am 11.10.2016 um 12:26 schrieb StDenis, Tom: > > That actually makes sense. It came up because mmPA_SC_RASTER_CONFIG > (and _1) are read by libdrm with a selection of 0/*/* for > se/sh/instance so I wanted to be able to reproduce that via the > debugfs interface for testing. > > > But ya, if you use the broadcast bit who are you reading from then ... > hmm.. > > > Tom > > > > ------------------------------------------------------------------------ > *From:* amd-gfx <amd-gfx-bounces at lists.freedesktop.org> on behalf of > Michel Dänzer <michel.daenzer at mailbox.org> > *Sent:* Monday, October 10, 2016 23:52 > *To:* Tom St Denis > *Cc:* amd-gfx at lists.freedesktop.org > *Subject:* Re: [PATCH] drm/amd/amdgpu: Allow broadcast on debugfs read > (v2) > On 09/10/16 08:58 PM, Tom St Denis wrote: > > Allow any of the se/sh/instance fields to be > > specified as a broadcast by submitting 0x3FF. > > > > (v2) Fix broadcast range checking > > > > Signed-off-by: Tom St Denis <tom.stdenis at amd.com> > > I'm not sure how a "broadcast read" is supposed to work? I can only see > the register specs talking about broadcast in connection with writes. > > > -- > Earthling Michel Dänzer | http://www.amd.com > <http://www.amd.com> > Graphics, Processors and Immersive VR Solutions | AMD > <http://www.amd.com/> > www.amd.com > Explore a wide range of innovative next generation computing > processors, graphics, and Immersive VR solutions by Advanced Micro > Devices (AMD). Visit AMD.com now! > > > > Libre software enthusiast | Mesa and X developer > _______________________________________________ > amd-gfx mailing list > amd-gfx at lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/amd-gfx > amd-gfx Info Page - lists.freedesktop.org > <https://lists.freedesktop.org/mailman/listinfo/amd-gfx> > lists.freedesktop.org > To see the collection of prior postings to the list, visit the amd-gfx > Archives. Using amd-gfx: To post a message to all the list members, > send email ... > > > > > > _______________________________________________ > amd-gfx mailing list > amd-gfx at lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/amd-gfx -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://lists.freedesktop.org/archives/amd-gfx/attachments/20161011/3cd52664/attachment-0001.html>
