Greetings. I have a framebuffer that is running under 2.4.3 on a MIPS platform. I also wrote a small little demo program that simply mmap's in the framebuffer in user space after which it simply moves the tux logo across the screen. The framebuffer is also used as the console and that also works great. After upgrading to 2.4.5, mmap no longer works. However, the console code works just fine i.e. the framebuffer console properly updates and displays things just fine on the screen. I can also do 'cat /bin/ls > /dev/fb0' and see garbage appear on the screen. Also, the virtual address returned by the mmap call for my demo program in user space is identical on 2.4.3 and 2.4.5, however no tux moves across the screen like it should for the 2.4.5 kernel meaning that the mmap call didn't actually get the framebuffer memory (that's my assumption). I have traced through 'do_mmap_pgoff' and that code appears to be nearly identical in 2.4.3 and 2.4.5. My architecture specific MM code has not changed either, so the cache flushing assembly code is identical. I'm working my way through the 'kmem_cache_XX' calls right now to find differences. Anyone have some ideas? Thanks. -Steve -- Steven J. Hill - Embedded SW Engineer
