From: "Antonino A. Daplas" - use vesafb_fix.line_length * vesafb_defined.yres to calculate the minimum memory required for a video mode. From Aurelien Jacobs . - separately calculate the memory required for a video mode, memory to be remapped, and total memory (for MTRR). From Gerd Knorr . - the 'vram' option is for memory to be remapped, not total memory. Signed-off-by: Antonino Daplas Signed-off-by: Andrew Morton --- 25-akpm/drivers/video/vesafb.c | 54 ++++++++++++++++++++++++----------------- 1 files changed, 32 insertions(+), 22 deletions(-) diff -puN drivers/video/vesafb.c~fbdev-fix-framebuffer-memory-calculation-for-vesafb drivers/video/vesafb.c --- 25/drivers/video/vesafb.c~fbdev-fix-framebuffer-memory-calculation-for-vesafb 2004-10-03 18:49:10.056508040 -0700 +++ 25-akpm/drivers/video/vesafb.c 2004-10-03 18:49:10.060507432 -0700 @@ -220,6 +220,9 @@ static int __init vesafb_probe(struct de struct platform_device *dev = to_platform_device(device); struct fb_info *info; int i, err; + unsigned int size_vmode; + unsigned int size_remap; + unsigned int size_total; if (screen_info.orig_video_isVGA != VIDEO_TYPE_VLFB) return -ENXIO; @@ -231,32 +234,37 @@ static int __init vesafb_probe(struct de vesafb_defined.xres = screen_info.lfb_width; vesafb_defined.yres = screen_info.lfb_height; vesafb_fix.line_length = screen_info.lfb_linelength; - - /* Allocate enough memory for double buffering */ - vesafb_fix.smem_len = screen_info.lfb_width * screen_info.lfb_height * vesafb_defined.bits_per_pixel >> 2; - - /* check that we don't remap more memory than old cards have */ - if (vesafb_fix.smem_len > (screen_info.lfb_size * 65536)) - vesafb_fix.smem_len = screen_info.lfb_size * 65536; - - /* Set video size according to vram boot option */ - if (vram) - vesafb_fix.smem_len = vram * 1024 * 1024; - vesafb_fix.visual = (vesafb_defined.bits_per_pixel == 8) ? FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_TRUECOLOR; - /* limit framebuffer size to 16 MB. Otherwise we'll eat tons of - * kernel address space for nothing if the gfx card has alot of - * memory (>= 128 MB isn't uncommon these days ...) */ - if (vesafb_fix.smem_len > 16 * 1024 * 1024) - vesafb_fix.smem_len = 16 * 1024 * 1024; + /* size_vmode -- that is the amount of memory needed for the + * used video mode, i.e. the minimum amount of + * memory we need. */ + size_vmode = vesafb_fix.line_length * vesafb_defined.yres; + + /* size_total -- all video memory we have. Used for mtrr + * entries and bounds checking. */ + size_total = screen_info.lfb_size * 65536; + if (size_total < size_vmode) + size_total = size_vmode; + + /* size_remap -- the amount of video memory we are going to + * use for vesafb. With modern cards it is no + * option to simply use size_total as that + * wastes plenty of kernel address space. */ + size_remap = size_vmode * 2; + if (vram) + size_remap = vram * 1024 * 1024; + + if (size_remap > size_total) + size_remap = size_total; + vesafb_fix.smem_len = size_remap; #ifndef __i386__ screen_info.vesapm_seg = 0; #endif - if (!request_mem_region(vesafb_fix.smem_start, vesafb_fix.smem_len, "vesafb")) { + if (!request_mem_region(vesafb_fix.smem_start, size_total, "vesafb")) { printk(KERN_WARNING "vesafb: abort, cannot reserve video memory at 0x%lx\n", vesafb_fix.smem_start); @@ -281,8 +289,10 @@ static int __init vesafb_probe(struct de goto err; } - printk(KERN_INFO "vesafb: framebuffer at 0x%lx, mapped to 0x%p, size %dk\n", - vesafb_fix.smem_start, info->screen_base, vesafb_fix.smem_len/1024); + printk(KERN_INFO "vesafb: framebuffer at 0x%lx, mapped to 0x%p, " + "using %dk, total %dk\n", + vesafb_fix.smem_start, info->screen_base, + size_remap/1024, size_total/1024); printk(KERN_INFO "vesafb: mode is %dx%dx%d, linelength=%d, pages=%d\n", vesafb_defined.xres, vesafb_defined.yres, vesafb_defined.bits_per_pixel, vesafb_fix.line_length, screen_info.pages); @@ -362,7 +372,7 @@ static int __init vesafb_probe(struct de request_region(0x3c0, 32, "vesafb"); if (mtrr) { - int temp_size = vesafb_fix.smem_len; + int temp_size = size_total; /* Find the largest power-of-two */ while (temp_size & (temp_size - 1)) temp_size &= (temp_size - 1); @@ -393,7 +403,7 @@ static int __init vesafb_probe(struct de return 0; err: framebuffer_release(info); - release_mem_region(vesafb_fix.smem_start, vesafb_fix.smem_len); + release_mem_region(vesafb_fix.smem_start, size_total); return err; } _