From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: In-Reply-To: <200006040709.JAA00760@piglet.grunz.lu> References: <00060311160100.00693@enzo.bigblue.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sun, 4 Jun 2000 10:08:39 -0500 To: mlan@cpu.lu, Franz.Sirl-kernel@lauterbach.com From: Tony Mantler Subject: Re: [patch] VRAM detection in controlfb Cc: linuxppc-dev@lists.linuxppc.org Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: At 2:09 AM -0500 6/4/2000, Michel Lanners wrote: >Hi Franz, > >On 3 Jun, this message from Franz Sirl echoed through cyberspace: >[hacking controlfb] >> if you don't mind, would you try to replace the "dcbi" assembler >>instructions >> in the detection code with "dcbf" instructions? It seems Dan inherited >>my bug >> I had in the platinumfb driver... > >Sure, no problem. > >In what sense is that a bug, and what would be the symptom? I know close >to nothing about PPC assembler, and fully understanding the detection >code might help fix the detection problems we still have in some >situations... dcbi = data cache block invalidate. If you do this on a dirty cache block, data will be lost. dcbf = data cache block flush. If you do this on a block that isn't in a coherent state, data will be lost. If you have a block that's both dirty and incoherent... well, don't do that. :) btw, my mail server messed up and I got bounced off the list a few weeks back, have I missed anything interesting? Cheers - Tony :) -- Tony Mantler Renaissance Nerd Extraordinaire nicoya@apia.dhs.org Winnipeg, Manitoba, Canada http://nicoya.feline.pp.se/ ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/