From: Antonino A. Daplas Date: Fri, 29 Jul 2005 21:03:31 +0000 (-0700) Subject: [PATCH] vesafb: Fix mtrr bugs X-Git-Tag: v2.6.13-rc5~66 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=80625942094b114d85811e5ff1fbc9e06dabe0ff;p=linux-2.6 [PATCH] vesafb: Fix mtrr bugs >> vesafb: mode is 800x600x16, linelength=1600, pages=16 >> vesafb: scrolling: redraw >> vesafb: Truecolor: size=0:5:6:5, shift=0:11:5:0 >> mtrr: type mismatch for fc000000,1000000 old: write-back new: write- >> combining Range is already set to write-back, vesafb attempts to add a write-combining mtrr (default for vesafb). >> mtrr: size and base must be multiples of 4 kiB This is a bug, vesafb attempts to add a size < PAGE_SIZE triggering the messages below. To eliminate the warning messages, you can add the option mtrr:2 to add a write-back mtrr for vesafb. Or just use nomtrr option. 1. Fix algorithm for finding the best power of 2 size with mtrr_add(). 2. Add option to choose the mtrr type by extending the mtrr boot option: mtrr:n where n 0 = no mtrr (equivalent to using the nomtrr option) 1 = uncachable 2 = write back 3 = write combining (default) 4 = write through Signed-off-by: Antonino Daplas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/video/vesafb.c b/drivers/video/vesafb.c index 9ed1a931dd..a272592b03 100644 --- a/drivers/video/vesafb.c +++ b/drivers/video/vesafb.c @@ -45,7 +45,7 @@ static struct fb_fix_screeninfo vesafb_fix __initdata = { }; static int inverse = 0; -static int mtrr = 1; +static int mtrr = 3; /* default to write-combining */ static int vram_remap __initdata = 0; /* Set amount of memory to be used */ static int vram_total __initdata = 0; /* Set total amount of memory */ static int pmi_setpal = 0; /* pmi for palette changes ??? */ @@ -204,8 +204,8 @@ static int __init vesafb_setup(char *options) pmi_setpal=0; else if (! strcmp(this_opt, "pmipal")) pmi_setpal=1; - else if (! strcmp(this_opt, "mtrr")) - mtrr=1; + else if (! strncmp(this_opt, "mtrr:", 5)) + mtrr = simple_strtoul(this_opt+5, NULL, 0); else if (! strcmp(this_opt, "nomtrr")) mtrr=0; else if (! strncmp(this_opt, "vtotal:", 7)) @@ -387,14 +387,39 @@ static int __init vesafb_probe(struct device *device) if (mtrr) { unsigned int temp_size = size_total; - /* Find the largest power-of-two */ - while (temp_size & (temp_size - 1)) - temp_size &= (temp_size - 1); - - /* Try and find a power of two to add */ - while (temp_size > PAGE_SIZE && - mtrr_add(vesafb_fix.smem_start, temp_size, MTRR_TYPE_WRCOMB, 1)==-EINVAL) { - temp_size >>= 1; + unsigned int type = 0; + + switch (mtrr) { + case 1: + type = MTRR_TYPE_UNCACHABLE; + break; + case 2: + type = MTRR_TYPE_WRBACK; + break; + case 3: + type = MTRR_TYPE_WRCOMB; + break; + case 4: + type = MTRR_TYPE_WRTHROUGH; + break; + default: + type = 0; + break; + } + + if (type) { + int rc; + + /* Find the largest power-of-two */ + while (temp_size & (temp_size - 1)) + temp_size &= (temp_size - 1); + + /* Try and find a power of two to add */ + do { + rc = mtrr_add(vesafb_fix.smem_start, temp_size, + type, 1); + temp_size >>= 1; + } while (temp_size >= PAGE_SIZE && rc == -EINVAL); } }