Re: [PATCH] grvga: Fix error handling issues

[Emil Goode <emilgoode@gmail.com>]

Good idea, I will take another look at it tomorrow.

Thanks, 

Emil

On Fri, 2012-06-22 at 18:12 +0200, Julia Lawall wrote:
> Maybe you could used the devm_ functions for request_mem_region and
> ioremap so that the error handling can just be dropped?
> 
> julia
> 
> On Fri, 22 Jun 2012, Emil Goode wrote:
> 
> > This patch fixes two problems with the error handling in the
> > grvga_probe function.
> >
> > - If the call to grvga_parse_custom on line 370 fails we use
> >   the wrong label so that release_mem_region will be called
> >   without a call to request_mem_region being made.
> >
> > - If the call to ioremap on line 436 fails we should not try
> >   to call iounmap. I added an if statement to check whether or
> >   not a call to iounmap should be made.
> >
> > - I also changed the names of the labels to make the code
> >   easier to read.
> >
> > Signed-off-by: Emil Goode <emilgoode@gmail.com>
> > ---
> >  drivers/video/grvga.c |   34 ++++++++++++++++++----------------
> >  1 file changed, 18 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/video/grvga.c b/drivers/video/grvga.c
> > index da066c2..d9d688a 100644
> > --- a/drivers/video/grvga.c
> > +++ b/drivers/video/grvga.c
> > @@ -354,7 +354,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
> >  	 */
> >  	if (fb_get_options("grvga", &options)) {
> >  		retval = -ENODEV;
> > -		goto err;
> > +		goto free_fb;
> >  	}
> >
> >  	if (!options || !*options)
> > @@ -370,7 +370,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
> >  			if (grvga_parse_custom(this_opt, &info->var) < 0) {
> >  				dev_err(&dev->dev, "Failed to parse custom mode (%s).\n", this_opt);
> >  				retval = -EINVAL;
> > -				goto err1;
> > +				goto free_fb;
> >  			}
> >  		} else if (!strncmp(this_opt, "addr", 4))
> >  			grvga_fix_addr = simple_strtoul(this_opt + 5, NULL, 16);
> > @@ -390,7 +390,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
> >  	if (!request_mem_region(dev->resource[0].start, resource_size(&dev->resource[0]), "grlib-svgactrl regs")) {
> >  		dev_err(&dev->dev, "registers already mapped\n");
> >  		retval = -EBUSY;
> > -		goto err;
> > +		goto free_fb;
> >  	}
> >
> >  	par->regs = of_ioremap(&dev->resource[0], 0,
> > @@ -400,14 +400,14 @@ static int __devinit grvga_probe(struct platform_device *dev)
> >  	if (!par->regs) {
> >  		dev_err(&dev->dev, "failed to map registers\n");
> >  		retval = -ENOMEM;
> > -		goto err1;
> > +		goto release_regs;
> >  	}
> >
> >  	retval = fb_alloc_cmap(&info->cmap, 256, 0);
> >  	if (retval < 0) {
> >  		dev_err(&dev->dev, "failed to allocate mem with fb_alloc_cmap\n");
> >  		retval = -ENOMEM;
> > -		goto err2;
> > +		goto unmap_regs;
> >  	}
> >
> >  	if (mode_opt) {
> > @@ -415,7 +415,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
> >  				      grvga_modedb, sizeof(grvga_modedb), &grvga_modedb[0], 8);
> >  		if (!retval || retval = 4) {
> >  			retval = -EINVAL;
> > -			goto err3;
> > +			goto dealloc_cmap;
> >  		}
> >  	}
> >
> > @@ -430,7 +430,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
> >  		if (!request_mem_region(physical_start, grvga_mem_size, dev->name)) {
> >  			dev_err(&dev->dev, "failed to request memory region\n");
> >  			retval = -ENOMEM;
> > -			goto err3;
> > +			goto dealloc_cmap;
> >  		}
> >
> >  		virtual_start = (unsigned long) ioremap(physical_start, grvga_mem_size);
> > @@ -438,7 +438,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
> >  		if (!virtual_start) {
> >  			dev_err(&dev->dev, "error mapping framebuffer memory\n");
> >  			retval = -ENOMEM;
> > -			goto err4;
> > +			goto free_mem;
> >  		}
> >  	} else {	/* Allocate frambuffer memory */
> >
> > @@ -451,7 +451,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
> >  				"unable to allocate framebuffer memory (%lu bytes)\n",
> >  				grvga_mem_size);
> >  			retval = -ENOMEM;
> > -			goto err3;
> > +			goto dealloc_cmap;
> >  		}
> >
> >  		physical_start = dma_map_single(&dev->dev, (void *)virtual_start, grvga_mem_size, DMA_TO_DEVICE);
> > @@ -484,7 +484,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
> >  	retval = register_framebuffer(info);
> >  	if (retval < 0) {
> >  		dev_err(&dev->dev, "failed to register framebuffer\n");
> > -		goto err4;
> > +		goto free_mem;
> >  	}
> >
> >  	__raw_writel(physical_start, &par->regs->fb_pos);
> > @@ -493,21 +493,23 @@ static int __devinit grvga_probe(struct platform_device *dev)
> >
> >  	return 0;
> >
> > -err4:
> > +free_mem:
> >  	dev_set_drvdata(&dev->dev, NULL);
> >  	if (grvga_fix_addr) {
> >  		release_mem_region(physical_start, grvga_mem_size);
> > -		iounmap((void *)virtual_start);
> > +		if (virtual_start)
> > +			iounmap((void *)virtual_start);
> >  	} else
> >  		kfree((void *)virtual_start);
> > -err3:
> > +
> > +dealloc_cmap:
> >  	fb_dealloc_cmap(&info->cmap);
> > -err2:
> > +unmap_regs:
> >  	of_iounmap(&dev->resource[0], par->regs,
> >  		   resource_size(&dev->resource[0]));
> > -err1:
> > +release_regs:
> >  	release_mem_region(dev->resource[0].start, resource_size(&dev->resource[0]));
> > -err:
> > +free_fb:
> >  	framebuffer_release(info);
> >
> >  	return retval;
> > --
> > 1.7.10
> >
> > --
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