From 537a1bf059fa312355696fa6db80726e655e7f17 Mon Sep 17 00:00:00 2001 From: Krzysztof Helt Date: Tue, 30 Jun 2009 11:41:29 -0700 Subject: 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 Cc: Peter Zijlstra Cc: "Rafael J. Wysocki" Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/video/sm501fb.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'drivers/video/sm501fb.c') 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) #define SM501_MEMF_ACCEL (8) static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem, - unsigned int why, size_t size) + unsigned int why, size_t size, u32 smem_len) { struct sm501fb_par *par; struct fb_info *fbi; @@ -172,7 +172,7 @@ static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem, if (ptr > 0) ptr &= ~(PAGE_SIZE - 1); - if (fbi && ptr < fbi->fix.smem_len) + if (fbi && ptr < smem_len) return -ENOMEM; break; @@ -197,7 +197,7 @@ static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem, case SM501_MEMF_ACCEL: fbi = inf->fb[HEAD_CRT]; - ptr = fbi ? fbi->fix.smem_len : 0; + ptr = fbi ? smem_len : 0; fbi = inf->fb[HEAD_PANEL]; if (fbi) { @@ -413,6 +413,7 @@ static int sm501fb_set_par_common(struct fb_info *info, unsigned int mem_type; unsigned int clock_type; unsigned int head_addr; + unsigned int smem_len; dev_dbg(fbi->dev, "%s: %dx%d, bpp = %d, virtual %dx%d\n", __func__, var->xres, var->yres, var->bits_per_pixel, @@ -453,18 +454,20 @@ static int sm501fb_set_par_common(struct fb_info *info, /* allocate fb memory within 501 */ info->fix.line_length = (var->xres_virtual * var->bits_per_pixel)/8; - info->fix.smem_len = info->fix.line_length * var->yres_virtual; + smem_len = info->fix.line_length * var->yres_virtual; dev_dbg(fbi->dev, "%s: line length = %u\n", __func__, info->fix.line_length); - if (sm501_alloc_mem(fbi, &par->screen, mem_type, - info->fix.smem_len)) { + if (sm501_alloc_mem(fbi, &par->screen, mem_type, smem_len, smem_len)) { dev_err(fbi->dev, "no memory available\n"); return -ENOMEM; } + mutex_lock(&info->mm_lock); info->fix.smem_start = fbi->fbmem_res->start + par->screen.sm_addr; + info->fix.smem_len = smem_len; + mutex_unlock(&info->mm_lock); info->screen_base = fbi->fbmem + par->screen.sm_addr; info->screen_size = info->fix.smem_len; @@ -637,7 +640,8 @@ static int sm501fb_set_par_crt(struct fb_info *info) if ((control & SM501_DC_CRT_CONTROL_SEL) == 0) { /* the head is displaying panel data... */ - sm501_alloc_mem(fbi, &par->screen, SM501_MEMF_CRT, 0); + sm501_alloc_mem(fbi, &par->screen, SM501_MEMF_CRT, 0, + info->fix.smem_len); goto out_update; } @@ -1289,7 +1293,8 @@ static int sm501_init_cursor(struct fb_info *fbi, unsigned int reg_base) par->cursor_regs = info->regs + reg_base; - ret = sm501_alloc_mem(info, &par->cursor, SM501_MEMF_CURSOR, 1024); + ret = sm501_alloc_mem(info, &par->cursor, SM501_MEMF_CURSOR, 1024, + fbi->fix.smem_len); if (ret < 0) return ret; -- cgit v1.2.3