Forgot this: One more possibility is to make the frame buffer region of address space cacheable but write-thru rather than copy-back.
a On Wed, 26 Jan 2000, Alan Mimms wrote: > We experimented at Apple with cacheable frame buffers and this is what we saw. > > I believe this is caused by the cache being on for the region of memory used > for the frame buffer. You'll see little 16 byte chunks of memory sparkling as > the cache finally dumps out dirty cache lines into the real frame buffer. > > You can fix this by mapping the area of the frame buffer with cache disabled, > or you can add code to some periodic timer handler to do a DCBF on the region > of the frame buffer each time the timer ticks (this is not cheap, however). > > a > > On > Wed, 26 Jan 2000, Shuangjun Zhu wrote: > Hello, everyone > > > > I'm using kernel version 2.2.13 on my MPC823 FADS board > > to display on TV. I have a problem: > > > > After the system boot up, the text on the TV flicker fiercely out, > > if I disable the I-Cache throught the EST visionProbe tool, > > TV will not flicker out again. > > Of course, if I disable the cache when the system boot up, > > TV display OK. > > So there is some relation between the cache and the video, I guess. > > > > > > Do you have any suggestion? > > Thanks in advacned! > > > > BRs, > > Shuangjun > -- > Alan Mimms Packet Engines, Inc. Spokane, Washington [99214-0497] > USA, Earth, Sol, Milky Way, The Local Group, Virgo Supercluster, U0 > Despite the cost of living, have you noticed how popular it remains? > -- Steven Wright? -- Alan Mimms Packet Engines, Inc. Spokane, Washington [99214-0497] USA, Earth, Sol, Milky Way, The Local Group, Virgo Supercluster, U0 Despite the cost of living, have you noticed how popular it remains? -- Steven Wright? ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
