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Date: Tue, 9 May 2006 23:01:49 -0400

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From: Mike Frysinger
Subject: [SDL] [patch] fall back to using MAP_PRIVATE with mmap() in fbcon dri

trying to use MAP_SHARED with mmap() on uClinux (aka non-mmu) hosts nowadays
will simply fail since the kernel disallows it ... falling back to using
MAP_PRIVATE on these hosts is acceptable ... as such, ive attached a patch
for the fbcon driver that will fall back to using MAP_PRIVATE if mmap() with
MAP_SHARED failed

going by a grep of MAP_SHARED, the only other drivers that utilize this flag
are video/wscons, video/ps2gs, and sound/dmaaudio ... i dont think these
would appear on a non-mmu host so the patch i wrote is restricted to just
SDL_fbvideo.c ...
-mike

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%401757
This commit is contained in:
Sam Lantinga 2006-05-10 04:05:46 +00:00
parent 4ff931d2b7
commit 24dd26200f
1 changed files with 15 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

17
src/video/fbcon/SDL_fbvideo.c
View file

@ -149,6 +149,19 @@ static void FB_SavePalette(_THIS, struct fb_fix_screeninfo *finfo,
struct fb_var_screeninfo *vinfo);
static void FB_RestorePalette(_THIS);
/* Small wrapper for mmap() so we can play nicely with no-mmu hosts
* (non-mmu hosts disallow the MAP_SHARED flag) */
static void *do_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
void *ret;
ret = mmap(start, length, prot, flags, fd, offset);
if ( ret == (char *)-1 && (flags & MAP_SHARED) ) {
ret = mmap(start, length, prot,
(flags & ~MAP_SHARED) | MAP_PRIVATE, fd, offset);
}
}
/* FB driver bootstrap functions */
static int FB_Available(void)
@ -535,7 +548,7 @@ static int FB_VideoInit(_THIS, SDL_PixelFormat *vformat)
mapped_offset = (((long)finfo.smem_start) -
(((long)finfo.smem_start)&~(PAGE_SIZE-1)));
mapped_memlen = finfo.smem_len+mapped_offset;
mapped_mem = mmap(NULL, mapped_memlen,
mapped_mem = do_mmap(NULL, mapped_memlen,
PROT_READ|PROT_WRITE, MAP_SHARED, console_fd, 0);
if ( mapped_mem == (char *)-1 ) {
SDL_SetError("Unable to memory map the video hardware");
@ -579,7 +592,7 @@ static int FB_VideoInit(_THIS, SDL_PixelFormat *vformat)
ioctl(console_fd, FBIOPUT_VSCREENINFO, &vinfo);
if ( finfo.accel && finfo.mmio_len ) {
mapped_iolen = finfo.mmio_len;
mapped_io = mmap(NULL, mapped_iolen, PROT_READ|PROT_WRITE,
mapped_io = do_mmap(NULL, mapped_iolen, PROT_READ|PROT_WRITE,
MAP_SHARED, console_fd, mapped_memlen);
if ( mapped_io == (char *)-1 ) {
/* Hmm, failed to memory map I/O registers */