On Fri, Oct 2, 2009 at 3:44 PM, Tony Lindgren <tony@xxxxxxxxxxx> wrote:
>
> From: Sergio Aguirre <saaguirre@xxxxxx>
>
> This fixes a bug introduced by this commit ID:
>
> commit 537a1bf059fa312355696fa6db80726e655e7f17
> Author: Krzysztof Helt <krzysztof.h1@xxxxx>
> Date: Tue Jun 30 11:41:29 2009 -0700
>
> fbdev: add mutex for fb_mmap locking
>
> In which a mutex was added when changing smem_start and smem_len fields,
> so the mutex inside the fb_mmap() call is actually used.
>
> The problem was that set_fb_fix, which modifies the above 2 fields,
> was called before and after registering the framebuffer,
> which when used before registration, lead to a failed attempt to
> use an uninitialized mutex.
>
> Solution: Don't use mutex before framebuffer registration.
>
> Signed-off-by: Sergio Aguirre <saaguirre@xxxxxx>
> Acked-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxx>
> Acked-by: Imre Deak <imre.deak@xxxxxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> ---
> drivers/video/omap/omapfb_main.c | 22 ++++++++++++++--------
> 1 files changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/video/omap/omapfb_main.c b/drivers/video/omap/omapfb_main.c
> index 125e605..0d0c8c8 100644
> --- a/drivers/video/omap/omapfb_main.c
> +++ b/drivers/video/omap/omapfb_main.c
> @@ -393,7 +393,7 @@ static void omapfb_sync(struct fb_info *fbi)
> * Set fb_info.fix fields and also updates fbdev.
> * When calling this fb_info.var must be set up already.
> */
> -static void set_fb_fix(struct fb_info *fbi)
> +static void set_fb_fix(struct fb_info *fbi, int from_init)
> {
> struct fb_fix_screeninfo *fix = &fbi->fix;
> struct fb_var_screeninfo *var = &fbi->var;
> @@ -403,10 +403,16 @@ static void set_fb_fix(struct fb_info *fbi)
>
> rg = &plane->fbdev->mem_desc.region[plane->idx];
> fbi->screen_base = rg->vaddr;
> - mutex_lock(&fbi->mm_lock);
> - fix->smem_start = rg->paddr;
> - fix->smem_len = rg->size;
> - mutex_unlock(&fbi->mm_lock);
> +
> + if (!from_init) {
> + mutex_lock(&fbi->mm_lock);
> + fix->smem_start = rg->paddr;
> + fix->smem_len = rg->size;
> + mutex_unlock(&fbi->mm_lock);
> + } else {
> + fix->smem_start = rg->paddr;
> + fix->smem_len = rg->size;
> + }
>
> fix->type = FB_TYPE_PACKED_PIXELS;
> bpp = var->bits_per_pixel;
> @@ -704,7 +710,7 @@ static int omapfb_set_par(struct fb_info *fbi)
> int r = 0;
>
> omapfb_rqueue_lock(fbdev);
> - set_fb_fix(fbi);
> + set_fb_fix(fbi, 0);
> r = ctrl_change_mode(fbi);
> omapfb_rqueue_unlock(fbdev);
>
> @@ -904,7 +910,7 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
> if (old_size != size) {
> if (size) {
> memcpy(&fbi->var, new_var, sizeof(fbi->var));
> - set_fb_fix(fbi);
> + set_fb_fix(fbi, 0);
> } else {
> /*
> * Set these explicitly to indicate that the
> @@ -1504,7 +1510,7 @@ static int fbinfo_init(struct omapfb_device *fbdev, struct fb_info *info)
> var->bits_per_pixel = fbdev->panel->bpp;
>
> set_fb_var(info, var);
> - set_fb_fix(info);
> + set_fb_fix(info, 1);
>
> r = fb_alloc_cmap(&info->cmap, 16, 0);
> if (r != 0)
>
> --
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Tested-by: Cory Maccarrone <darkstar6262@xxxxxxxxx>
This patch works beautifully for omap850-based devices. I need only
add a board file and LCD resolution parameters, and I get a fully
working framebuffer.
I have tested with linux-omap master (commit
6469d1c660f8751ff39836c81970cdbe46953057), adding only the board/lcd
files on HTC Herald.
- Cory
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