From mboxrd@z Thu Jan 1 00:00:00 1970 From: Moritz Muehlenhoff Subject: Re: [PATCH] radeonfb: (#2) Implement proper workarounds for PLL accesses Date: Sun, 10 Apr 2005 12:05:26 +0200 Message-ID: References: <1110519743.5810.13.camel@gaston> <1110672745.5787.60.camel@gaston> <1112743901.9568.67.camel@gaston> <1112827655.9518.194.camel@gaston> <21d7e9970504071422349426eb@mail.gmail.com> <1112914795.9568.320.camel@gaston> <1112923186.9567.349.camel@gaston> <1113005006.9568.402.camel@gaston> <1113089591.9518.440.camel@gaston> Return-path: In-Reply-To: <1113089591.9518.440.camel@gaston> Sender: linux-kernel-owner@vger.kernel.org List-Id: > radeonfb_setcolreg: INPLL >> radeonfb_setcolreg: OUTPLL >> radeonfb_setcolreg: OUTPLL >> ... last three lines repeated 63 times > > Hrm... the last (serie of 64 setcolreg) are probably X beeing extremely > dumb, and calling the ioctl 64 times to set each palette entry instead > of doing a single call for the whole palette... > > Anyway. Except for maybe the double set-par on switch from X to console, > there isn't much more we can do here. We might be able to improve X but > there is a significant lag between a fix done to X.org HEAD appears in > any distro. The fact is, according to ATI, there is a HW bug on M6 taht > can cause lockups of the chip, and this 5ms workaround is necessary to > avoid it... But it's not specific to X11; I've applied the patch you posted and the same symptoms occur for pure tty switching as well, the delay has decreased a bit (it's hard to measure, but around a second), but it's still rather annoying to work with. Is it distinguishable which M6 models are buggy? I'm using my X31 for about a year now and have probably made some tens of thousands of switches without lockups, so presumably not all models cause lockups. Cheers, Moritz