diff options
author | Andy Lutomirski <luto@amacapital.net> | 2013-05-13 19:58:46 -0400 |
---|---|---|
committer | Dave Airlie <airlied@redhat.com> | 2013-05-30 23:37:36 -0400 |
commit | 63e28a7a5ffce59b645ca9cbcc01e1e8be56bd75 (patch) | |
tree | 9f1772e41599f71bda18c71cc78480d7576e1b73 /Documentation | |
parent | 07ebea251d08ae851d501f7402359f053d038862 (diff) |
uvesafb: Clean up MTRR code
The old code allowed very strange memory types. Now it works like
all the other video drivers: ioremap_wc is used unconditionally,
and MTRRs are set if PAT is unavailable (unless MTRR is disabled
by a module parameter).
UC, WB, and WT support is gone. If there are MTRR conflicts that prevent
addition of a WC MTRR, adding a non-conflicting MTRR is pointless; it's
better to just turn off MTRR support entirely.
As an added bonus, any MTRR added is freed on unload.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/fb/uvesafb.txt | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/Documentation/fb/uvesafb.txt b/Documentation/fb/uvesafb.txt index eefdd91d298a..f6362d88763b 100644 --- a/Documentation/fb/uvesafb.txt +++ b/Documentation/fb/uvesafb.txt | |||
@@ -81,17 +81,11 @@ pmipal Use the protected mode interface for palette changes. | |||
81 | 81 | ||
82 | mtrr:n Setup memory type range registers for the framebuffer | 82 | mtrr:n Setup memory type range registers for the framebuffer |
83 | where n: | 83 | where n: |
84 | 0 - disabled (equivalent to nomtrr) (default) | 84 | 0 - disabled (equivalent to nomtrr) |
85 | 1 - uncachable | 85 | 3 - write-combining (default) |
86 | 2 - write-back | 86 | |
87 | 3 - write-combining | 87 | Values other than 0 and 3 will result in a warning and will be |
88 | 4 - write-through | 88 | treated just like 3. |
89 | |||
90 | If you see the following in dmesg, choose the type that matches | ||
91 | the old one. In this example, use "mtrr:2". | ||
92 | ... | ||
93 | mtrr: type mismatch for e0000000,8000000 old: write-back new: write-combining | ||
94 | ... | ||
95 | 89 | ||
96 | nomtrr Do not use memory type range registers. | 90 | nomtrr Do not use memory type range registers. |
97 | 91 | ||