Commit f0e2f38b authored by Francisco Jerez's avatar Francisco Jerez Committed by Dave Airlie

drm/ttm: fix caching problem on non-PAT systems.

http://bugzilla.kernel.org/show_bug.cgi?id=15328

This fixes a serious regression on AGP/non-PAT systems, where
pages were ending up in the wrong state and slowing down the
whole system.

[airlied: taken this from the bug as the other option is to revert
the change which caused it].

Tested-by: John W. Linville (in bug).
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 6a660f06
......@@ -196,14 +196,15 @@ EXPORT_SYMBOL(ttm_tt_populate);
#ifdef CONFIG_X86
static inline int ttm_tt_set_page_caching(struct page *p,
enum ttm_caching_state c_state)
enum ttm_caching_state c_old,
enum ttm_caching_state c_new)
{
int ret = 0;
if (PageHighMem(p))
return 0;
if (get_page_memtype(p) != -1) {
if (c_old != tt_cached) {
/* p isn't in the default caching state, set it to
* writeback first to free its current memtype. */
......@@ -212,16 +213,17 @@ static inline int ttm_tt_set_page_caching(struct page *p,
return ret;
}
if (c_state == tt_wc)
if (c_new == tt_wc)
ret = set_memory_wc((unsigned long) page_address(p), 1);
else if (c_state == tt_uncached)
else if (c_new == tt_uncached)
ret = set_pages_uc(p, 1);
return ret;
}
#else /* CONFIG_X86 */
static inline int ttm_tt_set_page_caching(struct page *p,
enum ttm_caching_state c_state)
enum ttm_caching_state c_old,
enum ttm_caching_state c_new)
{
return 0;
}
......@@ -254,7 +256,9 @@ static int ttm_tt_set_caching(struct ttm_tt *ttm,
for (i = 0; i < ttm->num_pages; ++i) {
cur_page = ttm->pages[i];
if (likely(cur_page != NULL)) {
ret = ttm_tt_set_page_caching(cur_page, c_state);
ret = ttm_tt_set_page_caching(cur_page,
ttm->caching_state,
c_state);
if (unlikely(ret != 0))
goto out_err;
}
......@@ -268,7 +272,7 @@ out_err:
for (j = 0; j < i; ++j) {
cur_page = ttm->pages[j];
if (likely(cur_page != NULL)) {
(void)ttm_tt_set_page_caching(cur_page,
(void)ttm_tt_set_page_caching(cur_page, c_state,
ttm->caching_state);
}
}
......
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