diff options
author | Krzysztof Helt <krzysztof.h1@wp.pl> | 2009-06-30 14:41:29 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-30 21:56:00 -0400 |
commit | 537a1bf059fa312355696fa6db80726e655e7f17 (patch) | |
tree | 4f5b3c6917311cfefad21eaf3dd92978334282de /drivers/video/sm501fb.c | |
parent | 70d6027ff2bc8bab180273b77e7ab3e8a62cca51 (diff) |
fbdev: add mutex for fb_mmap locking
Add a mutex to avoid a circular locking problem between the mm layer
semaphore and fbdev ioctl mutex through the fb_mmap() call.
Also, add mutex to all places where smem_start and smem_len fields change
so the mutex inside the fb_mmap() is actually used. Changing of these
fields before calling the framebuffer_register() are not mutexed.
This is 2.6.31 material. It removes one lockdep (fb_mmap() and
register_framebuffer()) but there is still another one (fb_release() and
register_framebuffer()). It also cleans up handling of the smem_start and
smem_len fields used by mutexed section of the fb_mmap().
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video/sm501fb.c')
-rw-r--r-- | drivers/video/sm501fb.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/video/sm501fb.c b/drivers/video/sm501fb.c index eb5d73a06702..98f24f0ec00d 100644 --- a/drivers/video/sm501fb.c +++ b/drivers/video/sm501fb.c | |||
@@ -145,7 +145,7 @@ static inline void sm501fb_sync_regs(struct sm501fb_info *info) | |||
145 | #define SM501_MEMF_ACCEL (8) | 145 | #define SM501_MEMF_ACCEL (8) |
146 | 146 | ||
147 | static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem, | 147 | static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem, |
148 | unsigned int why, size_t size) | 148 | unsigned int why, size_t size, u32 smem_len) |
149 | { | 149 | { |
150 | struct sm501fb_par *par; | 150 | struct sm501fb_par *par; |
151 | struct fb_info *fbi; | 151 | struct fb_info *fbi; |
@@ -172,7 +172,7 @@ static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem, | |||
172 | if (ptr > 0) | 172 | if (ptr > 0) |
173 | ptr &= ~(PAGE_SIZE - 1); | 173 | ptr &= ~(PAGE_SIZE - 1); |
174 | 174 | ||
175 | if (fbi && ptr < fbi->fix.smem_len) | 175 | if (fbi && ptr < smem_len) |
176 | return -ENOMEM; | 176 | return -ENOMEM; |
177 | 177 | ||
178 | break; | 178 | break; |
@@ -197,7 +197,7 @@ static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem, | |||
197 | 197 | ||
198 | case SM501_MEMF_ACCEL: | 198 | case SM501_MEMF_ACCEL: |
199 | fbi = inf->fb[HEAD_CRT]; | 199 | fbi = inf->fb[HEAD_CRT]; |
200 | ptr = fbi ? fbi->fix.smem_len : 0; | 200 | ptr = fbi ? smem_len : 0; |
201 | 201 | ||
202 | fbi = inf->fb[HEAD_PANEL]; | 202 | fbi = inf->fb[HEAD_PANEL]; |
203 | if (fbi) { | 203 | if (fbi) { |
@@ -413,6 +413,7 @@ static int sm501fb_set_par_common(struct fb_info *info, | |||
413 | unsigned int mem_type; | 413 | unsigned int mem_type; |
414 | unsigned int clock_type; | 414 | unsigned int clock_type; |
415 | unsigned int head_addr; | 415 | unsigned int head_addr; |
416 | unsigned int smem_len; | ||
416 | 417 | ||
417 | dev_dbg(fbi->dev, "%s: %dx%d, bpp = %d, virtual %dx%d\n", | 418 | dev_dbg(fbi->dev, "%s: %dx%d, bpp = %d, virtual %dx%d\n", |
418 | __func__, var->xres, var->yres, var->bits_per_pixel, | 419 | __func__, var->xres, var->yres, var->bits_per_pixel, |
@@ -453,18 +454,20 @@ static int sm501fb_set_par_common(struct fb_info *info, | |||
453 | 454 | ||
454 | /* allocate fb memory within 501 */ | 455 | /* allocate fb memory within 501 */ |
455 | info->fix.line_length = (var->xres_virtual * var->bits_per_pixel)/8; | 456 | info->fix.line_length = (var->xres_virtual * var->bits_per_pixel)/8; |
456 | info->fix.smem_len = info->fix.line_length * var->yres_virtual; | 457 | smem_len = info->fix.line_length * var->yres_virtual; |
457 | 458 | ||
458 | dev_dbg(fbi->dev, "%s: line length = %u\n", __func__, | 459 | dev_dbg(fbi->dev, "%s: line length = %u\n", __func__, |
459 | info->fix.line_length); | 460 | info->fix.line_length); |
460 | 461 | ||
461 | if (sm501_alloc_mem(fbi, &par->screen, mem_type, | 462 | if (sm501_alloc_mem(fbi, &par->screen, mem_type, smem_len, smem_len)) { |
462 | info->fix.smem_len)) { | ||
463 | dev_err(fbi->dev, "no memory available\n"); | 463 | dev_err(fbi->dev, "no memory available\n"); |
464 | return -ENOMEM; | 464 | return -ENOMEM; |
465 | } | 465 | } |
466 | 466 | ||
467 | mutex_lock(&info->mm_lock); | ||
467 | info->fix.smem_start = fbi->fbmem_res->start + par->screen.sm_addr; | 468 | info->fix.smem_start = fbi->fbmem_res->start + par->screen.sm_addr; |
469 | info->fix.smem_len = smem_len; | ||
470 | mutex_unlock(&info->mm_lock); | ||
468 | 471 | ||
469 | info->screen_base = fbi->fbmem + par->screen.sm_addr; | 472 | info->screen_base = fbi->fbmem + par->screen.sm_addr; |
470 | info->screen_size = info->fix.smem_len; | 473 | info->screen_size = info->fix.smem_len; |
@@ -637,7 +640,8 @@ static int sm501fb_set_par_crt(struct fb_info *info) | |||
637 | if ((control & SM501_DC_CRT_CONTROL_SEL) == 0) { | 640 | if ((control & SM501_DC_CRT_CONTROL_SEL) == 0) { |
638 | /* the head is displaying panel data... */ | 641 | /* the head is displaying panel data... */ |
639 | 642 | ||
640 | sm501_alloc_mem(fbi, &par->screen, SM501_MEMF_CRT, 0); | 643 | sm501_alloc_mem(fbi, &par->screen, SM501_MEMF_CRT, 0, |
644 | info->fix.smem_len); | ||
641 | goto out_update; | 645 | goto out_update; |
642 | } | 646 | } |
643 | 647 | ||
@@ -1289,7 +1293,8 @@ static int sm501_init_cursor(struct fb_info *fbi, unsigned int reg_base) | |||
1289 | 1293 | ||
1290 | par->cursor_regs = info->regs + reg_base; | 1294 | par->cursor_regs = info->regs + reg_base; |
1291 | 1295 | ||
1292 | ret = sm501_alloc_mem(info, &par->cursor, SM501_MEMF_CURSOR, 1024); | 1296 | ret = sm501_alloc_mem(info, &par->cursor, SM501_MEMF_CURSOR, 1024, |
1297 | fbi->fix.smem_len); | ||
1293 | if (ret < 0) | 1298 | if (ret < 0) |
1294 | return ret; | 1299 | return ret; |
1295 | 1300 | ||