[PATCH] ARM: PXA: Make PXA27x/PXA3xx overlay actually work

Eric Miao eric.y.miao at gmail.com
Tue Feb 15 02:35:44 EST 2011


On Thu, Feb 3, 2011 at 4:46 AM, Vasily Khoruzhick <anarsoul at gmail.com> wrote:
> From: "Russell King - ARM Linux" <linux at arm.linux.org.uk>
>
> Release callback tries to free memory even if it was not allocated in
> map_video_memory. Fix PXA27x/3xx overlay memory management and make overlay
> actually work.

That's indeed an issue.

>
> Added by Vasily Khoruzhick:
>
> - Move overlay Z-ordering selection into main fb initialization,
> otherwise plane ordering is wrong.
> - Clear x_res/y_res fields of fb.var on release, to make sure
> our callback will be called on next FBIOPUT_VSCREENINFO ioctl.
> - Disable overlay only if it was enabled.

The patch looks generally OK to me, some points for discussion
below though:

>
> Signed-off-by: Vasily Khoruzhick <anarsoul at gmail.com>
> ---
>  drivers/video/pxafb.c |   86 ++++++++++++++++++++++++++++++------------------
>  drivers/video/pxafb.h |    2 +-
>  2 files changed, 55 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/video/pxafb.c b/drivers/video/pxafb.c
> index 825b665..33f607a 100644
> --- a/drivers/video/pxafb.c
> +++ b/drivers/video/pxafb.c
> @@ -629,16 +629,19 @@ static void overlay1fb_disable(struct pxafb_layer *ofb)
>  {
>        uint32_t lccr5 = lcd_readl(ofb->fbi, LCCR5);
>

Or maybe simply:

	if (lcd_readl(ofb->fbi, OVL1C1) & OVLxC1_OEN)
		return;

this makes this block of change much cleaner.

> -       lcd_writel(ofb->fbi, OVL1C1, ofb->control[0] & ~OVLxC1_OEN);
> +       if (lcd_readl(ofb->fbi, OVL1C1) & OVLxC1_OEN) {
> +               lcd_writel(ofb->fbi, OVL1C1, ofb->control[0] & ~OVLxC1_OEN);
>
> -       lcd_writel(ofb->fbi, LCSR1, LCSR1_BS(1));
> -       lcd_writel(ofb->fbi, LCCR5, lccr5 & ~LCSR1_BS(1));
> -       lcd_writel(ofb->fbi, FBR1, ofb->fbi->fdadr[DMA_OV1] | 0x3);
> +               lcd_writel(ofb->fbi, LCSR1, LCSR1_BS(1));
> +               lcd_writel(ofb->fbi, LCCR5, lccr5 & ~LCSR1_BS(1));
> +               lcd_writel(ofb->fbi, FBR1, ofb->fbi->fdadr[DMA_OV1] | 0x3);
>
> -       if (wait_for_completion_timeout(&ofb->branch_done, 1 * HZ) == 0)
> -               pr_warning("%s: timeout disabling overlay1\n", __func__);
> +               if (wait_for_completion_timeout(&ofb->branch_done, 1 * HZ) == 0)
> +                       pr_warning("%s: timeout disabling overlay1\n",
> +                               __func__);
>
> -       lcd_writel(ofb->fbi, LCCR5, lccr5);
> +               lcd_writel(ofb->fbi, LCCR5, lccr5);
> +       }
>  }
>
>  static void overlay2fb_setup(struct pxafb_layer *ofb)
> @@ -687,16 +690,19 @@ static void overlay2fb_disable(struct pxafb_layer *ofb)
>  {
>        uint32_t lccr5 = lcd_readl(ofb->fbi, LCCR5);
>
> -       lcd_writel(ofb->fbi, OVL2C1, ofb->control[0] & ~OVLxC1_OEN);
> +       if (lcd_readl(ofb->fbi, OVL2C1) & OVLxC1_OEN) {
> +               lcd_writel(ofb->fbi, OVL2C1, ofb->control[0] & ~OVLxC1_OEN);

Ditto.

>
> -       lcd_writel(ofb->fbi, LCSR1, LCSR1_BS(2));
> -       lcd_writel(ofb->fbi, LCCR5, lccr5 & ~LCSR1_BS(2));
> -       lcd_writel(ofb->fbi, FBR2, ofb->fbi->fdadr[DMA_OV2_Y]  | 0x3);
> -       lcd_writel(ofb->fbi, FBR3, ofb->fbi->fdadr[DMA_OV2_Cb] | 0x3);
> -       lcd_writel(ofb->fbi, FBR4, ofb->fbi->fdadr[DMA_OV2_Cr] | 0x3);
> +               lcd_writel(ofb->fbi, LCSR1, LCSR1_BS(2));
> +               lcd_writel(ofb->fbi, LCCR5, lccr5 & ~LCSR1_BS(2));
> +               lcd_writel(ofb->fbi, FBR2, ofb->fbi->fdadr[DMA_OV2_Y]  | 0x3);
> +               lcd_writel(ofb->fbi, FBR3, ofb->fbi->fdadr[DMA_OV2_Cb] | 0x3);
> +               lcd_writel(ofb->fbi, FBR4, ofb->fbi->fdadr[DMA_OV2_Cr] | 0x3);
>
> -       if (wait_for_completion_timeout(&ofb->branch_done, 1 * HZ) == 0)
> -               pr_warning("%s: timeout disabling overlay2\n", __func__);
> +               if (wait_for_completion_timeout(&ofb->branch_done, 1 * HZ) == 0)
> +                       pr_warning("%s: timeout disabling overlay2\n",
> +                               __func__);
> +       }
>  }
>
>  static struct pxafb_layer_ops ofb_ops[] = {
> @@ -720,12 +726,10 @@ static int overlayfb_open(struct fb_info *info, int user)
>        if (user == 0)
>                return -ENODEV;
>
> -       /* allow only one user at a time */
> -       if (atomic_inc_and_test(&ofb->usage))
> -               return -EBUSY;
> +       if (ofb->usage++ == 0)
> +               /* unblank the base framebuffer */
> +               fb_blank(&ofb->fbi->fb, FB_BLANK_UNBLANK);

The change above allows multiple user at a time? Then I guess
some other places need to be changed accordingly to avoid the
racing conditions.

If this is a feature request, can we postpone it to subsequent
patches?

>
> -       /* unblank the base framebuffer */
> -       fb_blank(&ofb->fbi->fb, FB_BLANK_UNBLANK);
>        return 0;
>  }
>
> @@ -733,12 +737,24 @@ static int overlayfb_release(struct fb_info *info, int user)
>  {
>        struct pxafb_layer *ofb = (struct pxafb_layer*) info;
>
> -       atomic_dec(&ofb->usage);
> -       ofb->ops->disable(ofb);
> -
> -       free_pages_exact(ofb->video_mem, ofb->video_mem_size);
> -       ofb->video_mem = NULL;
> -       ofb->video_mem_size = 0;
> +       if (--ofb->usage == 0) {
> +               ofb->ops->disable(ofb);
> +               ofb->fb.var.height      = -1;
> +               ofb->fb.var.width       = -1;
> +               ofb->fb.var.xres = ofb->fb.var.xres_virtual = 0;
> +               ofb->fb.var.yres = ofb->fb.var.yres_virtual = 0;
> +
> +               mutex_lock(&ofb->fb.mm_lock);
> +               ofb->fb.fix.smem_start  = 0;
> +               ofb->fb.fix.smem_len    = 0;
> +               mutex_unlock(&ofb->fb.mm_lock);
> +
> +               if (ofb->video_mem) {
> +                       free_pages_exact(ofb->video_mem, ofb->video_mem_size);
> +                       ofb->video_mem = NULL;
> +                       ofb->video_mem_size = 0;
> +               }
> +       }
>        return 0;
>  }
>
> @@ -817,7 +833,8 @@ static int overlayfb_map_video_memory(struct pxafb_layer *ofb)
>                if (ofb->video_mem_size >= size)
>                        return 0;
>
> -               free_pages_exact(ofb->video_mem, ofb->video_mem_size);
> +               /* don't re-allocate: userspace may have the buffer mapped */
> +               return -EINVAL;
>        }
>
>        ofb->video_mem = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
> @@ -891,7 +908,7 @@ static void __devinit init_pxafb_overlay(struct pxafb_info *fbi,
>
>        ofb->id = id;
>        ofb->ops = &ofb_ops[id];
> -       atomic_set(&ofb->usage, 0);
> +       ofb->usage = 0;
>        ofb->fbi = fbi;
>        init_completion(&ofb->branch_done);
>  }
> @@ -923,8 +940,6 @@ static int __devinit pxafb_overlay_init(struct pxafb_info *fbi)
>        /* mask all IU/BS/EOF/SOF interrupts */
>        lcd_writel(fbi, LCCR5, ~0);
>
> -       /* place overlay(s) on top of base */
> -       fbi->lccr0 |= LCCR0_OUC;
>        pr_info("PXA Overlay driver loaded successfully!\n");
>        return 0;
>  }
> @@ -1368,7 +1383,8 @@ static int pxafb_activate_var(struct fb_var_screeninfo *var,
>            (lcd_readl(fbi, LCCR3) != fbi->reg_lccr3) ||
>            (lcd_readl(fbi, LCCR4) != fbi->reg_lccr4) ||
>            (lcd_readl(fbi, FDADR0) != fbi->fdadr[0]) ||
> -           (lcd_readl(fbi, FDADR1) != fbi->fdadr[1]))
> +           ((fbi->lccr0 & LCCR0_SDS) &&
> +           (lcd_readl(fbi, FDADR1) != fbi->fdadr[1])))
>                pxafb_schedule_work(fbi, C_REENABLE);
>
>        return 0;
> @@ -1420,7 +1436,8 @@ static void pxafb_enable_controller(struct pxafb_info *fbi)
>        lcd_writel(fbi, LCCR0, fbi->reg_lccr0 & ~LCCR0_ENB);
>
>        lcd_writel(fbi, FDADR0, fbi->fdadr[0]);
> -       lcd_writel(fbi, FDADR1, fbi->fdadr[1]);
> +       if (fbi->lccr0 & LCCR0_SDS)
> +               lcd_writel(fbi, FDADR1, fbi->fdadr[1]);

My original intention was to simplify the code a bit by ignoring
LCCR0_SDS, as FDADR1 would not take effect if not enabled even
if it's being read/written.

>        lcd_writel(fbi, LCCR0, fbi->reg_lccr0 | LCCR0_ENB);
>  }
>
> @@ -1806,6 +1823,11 @@ static struct pxafb_info * __devinit pxafb_init_fbinfo(struct device *dev)
>
>        pxafb_decode_mach_info(fbi, inf);
>
> +#ifdef CONFIG_FB_PXA_OVERLAY
> +       if (cpu_is_pxa27x())
> +               fbi->lccr0 |= LCCR0_OUC;
> +#endif
> +

I seem to remember LCCR0_OUC is still valid on pxa3xx, did you
do some test on pxa3xx as well?

>        init_waitqueue_head(&fbi->ctrlr_wait);
>        INIT_WORK(&fbi->task, pxafb_task);
>        mutex_init(&fbi->ctrlr_lock);
> diff --git a/drivers/video/pxafb.h b/drivers/video/pxafb.h
> index 2353521..84e3ae1 100644
> --- a/drivers/video/pxafb.h
> +++ b/drivers/video/pxafb.h
> @@ -92,7 +92,7 @@ struct pxafb_layer_ops {
>  struct pxafb_layer {
>        struct fb_info          fb;
>        int                     id;
> -       atomic_t                usage;
> +       uint32_t                usage;
>        uint32_t                control[2];
>
>        struct pxafb_layer_ops  *ops;
> --
> 1.7.4.rc1
>
>



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