[PATCH 1/4] ARM: PXA: PXAFB: rework pxafb overlay memory management

Marek Vasut marek.vasut at gmail.com
Fri Mar 11 16:34:10 EST 2011


On Friday 11 March 2011 10:20:47 Vasily Khoruzhick wrote:
> PXAFB overlay memory management is something messy:
> - it allocates memory dynamically on open/release, and it results
>   in memory allocation failure after ~1h of uptime (system does not have
>   115k of physically contiguous memory)
> - in release callback it tries to free memory even if it was not
>   allocated.
> 
> Also driver touches FDADR1 on main plane reconfiguration, and it can cause
> problems if overlay1 is enabled.
> 
> This patch attempts to fix those issues.
> 
> Patch is based on Russell King's work.
> 
> Signed-off-by: Vasily Khoruzhick <anarsoul at gmail.com>
> ---
>  drivers/video/pxafb.c |  121
> ++++++++++++++++++++++++++++++++----------------- drivers/video/pxafb.h | 
>   3 +-
>  2 files changed, 81 insertions(+), 43 deletions(-)
> 
> diff --git a/drivers/video/pxafb.c b/drivers/video/pxafb.c
> index 825b665..0764759 100644
> --- a/drivers/video/pxafb.c
> +++ b/drivers/video/pxafb.c
> @@ -627,7 +627,12 @@ static void overlay1fb_enable(struct pxafb_layer *ofb)
> 
>  static void overlay1fb_disable(struct pxafb_layer *ofb)
>  {
> -	uint32_t lccr5 = lcd_readl(ofb->fbi, LCCR5);
> +	uint32_t lccr5;
> +
> +	if (!(lcd_readl(ofb->fbi, OVL1C1) & OVLxC1_OEN))
> +		return;
> +
> +	lccr5 = lcd_readl(ofb->fbi, LCCR5);
> 
>  	lcd_writel(ofb->fbi, OVL1C1, ofb->control[0] & ~OVLxC1_OEN);
> 
> @@ -685,7 +690,12 @@ static void overlay2fb_enable(struct pxafb_layer *ofb)
> 
>  static void overlay2fb_disable(struct pxafb_layer *ofb)
>  {
> -	uint32_t lccr5 = lcd_readl(ofb->fbi, LCCR5);
> +	uint32_t lccr5;
> +
> +	if (!(lcd_readl(ofb->fbi, OVL2C1) & OVLxC1_OEN))
> +		return;
> +
> +	lccr5 = lcd_readl(ofb->fbi, LCCR5);
> 
>  	lcd_writel(ofb->fbi, OVL2C1, ofb->control[0] & ~OVLxC1_OEN);
> 
> @@ -720,12 +730,10 @@ 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)

TBH I don't like this notation, it feels hard to read. Can you split that ofb-
>usage++ into two parts ?

Cheers

> +		/* unblank the base framebuffer */
> +		fb_blank(&ofb->fbi->fb, FB_BLANK_UNBLANK);
> 
> -	/* unblank the base framebuffer */
> -	fb_blank(&ofb->fbi->fb, FB_BLANK_UNBLANK);
>  	return 0;
>  }
> 
> @@ -733,12 +741,15 @@ 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);
> +	if (ofb->usage == 1) {
> +		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;
> 
> -	free_pages_exact(ofb->video_mem, ofb->video_mem_size);
> -	ofb->video_mem = NULL;
> -	ofb->video_mem_size = 0;
> +		ofb->usage--;
> +	}
>  	return 0;
>  }
> 
> @@ -794,7 +805,7 @@ static int overlayfb_check_var(struct fb_var_screeninfo
> *var, return 0;
>  }
> 
> -static int overlayfb_map_video_memory(struct pxafb_layer *ofb)
> +static int overlayfb_check_video_memory(struct pxafb_layer *ofb)
>  {
>  	struct fb_var_screeninfo *var = &ofb->fb.var;
>  	int pfor = NONSTD_TO_PFOR(var->nonstd);
> @@ -812,27 +823,11 @@ static int overlayfb_map_video_memory(struct
> pxafb_layer *ofb)
> 
>  	size = PAGE_ALIGN(ofb->fb.fix.line_length * var->yres_virtual);
> 
> -	/* don't re-allocate if the original video memory is enough */
>  	if (ofb->video_mem) {
>  		if (ofb->video_mem_size >= size)
>  			return 0;
> -
> -		free_pages_exact(ofb->video_mem, ofb->video_mem_size);
>  	}
> -
> -	ofb->video_mem = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
> -	if (ofb->video_mem == NULL)
> -		return -ENOMEM;
> -
> -	ofb->video_mem_phys = virt_to_phys(ofb->video_mem);
> -	ofb->video_mem_size = size;
> -
> -	mutex_lock(&ofb->fb.mm_lock);
> -	ofb->fb.fix.smem_start	= ofb->video_mem_phys;
> -	ofb->fb.fix.smem_len	= ofb->fb.fix.line_length * var->yres_virtual;
> -	mutex_unlock(&ofb->fb.mm_lock);
> -	ofb->fb.screen_base	= ofb->video_mem;
> -	return 0;
> +	return -EINVAL;
>  }
> 
>  static int overlayfb_set_par(struct fb_info *info)
> @@ -841,7 +836,7 @@ static int overlayfb_set_par(struct fb_info *info)
>  	struct fb_var_screeninfo *var = &info->var;
>  	int xpos, ypos, pfor, bpp, ret;
> 
> -	ret = overlayfb_map_video_memory(ofb);
> +	ret = overlayfb_check_video_memory(ofb);
>  	if (ret)
>  		return ret;
> 
> @@ -891,7 +886,7 @@ 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);
>  }
> @@ -904,20 +899,54 @@ static inline int pxafb_overlay_supported(void)
>  	return 0;
>  }
> 
> -static int __devinit pxafb_overlay_init(struct pxafb_info *fbi)
> +static int __devinit pxafb_overlay_map_video_memory(struct pxafb_info
> *pxafb, +	struct pxafb_layer *ofb)
> +{
> +	/* We assume that user will use at most video_mem_size for overlay fb,
> +	 * anyway, it's useless to use 16bpp main plane and 24bpp overlay
> +	 */
> +	ofb->video_mem = alloc_pages_exact(PAGE_ALIGN(pxafb->video_mem_size),
> +		GFP_KERNEL | __GFP_ZERO);
> +	if (ofb->video_mem == NULL)
> +		return -ENOMEM;
> +
> +	ofb->video_mem_phys = virt_to_phys(ofb->video_mem);
> +	ofb->video_mem_size = PAGE_ALIGN(pxafb->video_mem_size);
> +
> +	mutex_lock(&ofb->fb.mm_lock);
> +	ofb->fb.fix.smem_start	= ofb->video_mem_phys;
> +	ofb->fb.fix.smem_len	= pxafb->video_mem_size;
> +	mutex_unlock(&ofb->fb.mm_lock);
> +
> +	ofb->fb.screen_base	= ofb->video_mem;
> +
> +	return 0;
> +}
> +
> +static void __devinit pxafb_overlay_init(struct pxafb_info *fbi)
>  {
>  	int i, ret;
> 
>  	if (!pxafb_overlay_supported())
> -		return 0;
> +		return;
> 
>  	for (i = 0; i < 2; i++) {
> -		init_pxafb_overlay(fbi, &fbi->overlay[i], i);
> -		ret = register_framebuffer(&fbi->overlay[i].fb);
> +		struct pxafb_layer *ofb = &fbi->overlay[i];
> +		init_pxafb_overlay(fbi, ofb, i);
> +		ret = register_framebuffer(&ofb->fb);
>  		if (ret) {
>  			dev_err(fbi->dev, "failed to register overlay %d\n", i);
> -			return ret;
> +			continue;
> +		}
> +		ret = pxafb_overlay_map_video_memory(fbi, ofb);
> +		if (ret) {
> +			dev_err(fbi->dev,
> +				"failed to map video memory for overlay %d\n",
> +				i);
> +			unregister_framebuffer(&ofb->fb);
> +			continue;
>  		}
> +		ofb->registered = 1;
>  	}
> 
>  	/* mask all IU/BS/EOF/SOF interrupts */
> @@ -926,7 +955,6 @@ static int __devinit pxafb_overlay_init(struct
> pxafb_info *fbi) /* place overlay(s) on top of base */
>  	fbi->lccr0 |= LCCR0_OUC;
>  	pr_info("PXA Overlay driver loaded successfully!\n");
> -	return 0;
>  }
> 
>  static void __devexit pxafb_overlay_exit(struct pxafb_info *fbi)
> @@ -936,8 +964,15 @@ static void __devexit pxafb_overlay_exit(struct
> pxafb_info *fbi) if (!pxafb_overlay_supported())
>  		return;
> 
> -	for (i = 0; i < 2; i++)
> -		unregister_framebuffer(&fbi->overlay[i].fb);
> +	for (i = 0; i < 2; i++) {
> +		struct pxafb_layer *ofb = &fbi->overlay[i];
> +		if (ofb->registered) {
> +			if (ofb->video_mem)
> +				free_pages_exact(ofb->video_mem,
> +					ofb->video_mem_size);
> +			unregister_framebuffer(&ofb->fb);
> +		}
> +	}
>  }
>  #else
>  static inline void pxafb_overlay_init(struct pxafb_info *fbi) {}
> @@ -1368,7 +1403,8 @@ 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 +1456,8 @@ 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]);
>  	lcd_writel(fbi, LCCR0, fbi->reg_lccr0 | LCCR0_ENB);
>  }
> 
> diff --git a/drivers/video/pxafb.h b/drivers/video/pxafb.h
> index 2353521..26ba9fa 100644
> --- a/drivers/video/pxafb.h
> +++ b/drivers/video/pxafb.h
> @@ -92,7 +92,8 @@ struct pxafb_layer_ops {
>  struct pxafb_layer {
>  	struct fb_info		fb;
>  	int			id;
> -	atomic_t		usage;
> +	int			registered;
> +	uint32_t		usage;
>  	uint32_t		control[2];
> 
>  	struct pxafb_layer_ops	*ops;



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