video: fbdev: imxfb: Convert request_mem_region + ioremap to devm_ioremap_resource

This has several advantages:

 - No need for manual undo of the two functions in the error path and
   the remove function.
 - Drops error handling in .remove()
   Note that returning early in .remove() yields resource leaks that
   often result in access of freed memory or unmapped registers later.
 - Fixes a resource leak
   request_mem_region allocates memory for the returned pointer that was
   never freed.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/drivers/video/fbdev/imxfb.c b/drivers/video/fbdev/imxfb.c
index fa6a19c..c484778 100644 (file)
--- a/drivers/video/fbdev/imxfb.c
+++ b/drivers/video/fbdev/imxfb.c
@@ -937,13 +937,6 @@ static int imxfb_probe(struct platform_device *pdev)
                info->fix.smem_len = max_t(size_t, info->fix.smem_len,
                                m->mode.xres * m->mode.yres * bytes_per_pixel);
 
-       res = request_mem_region(res->start, resource_size(res),
-                               DRIVER_NAME);
-       if (!res) {
-               ret = -EBUSY;
-               goto failed_req;
-       }
-
        fbi->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
        if (IS_ERR(fbi->clk_ipg)) {
                ret = PTR_ERR(fbi->clk_ipg);
@@ -977,7 +970,7 @@ static int imxfb_probe(struct platform_device *pdev)
                goto failed_getclock;
        }
 
-       fbi->regs = ioremap(res->start, resource_size(res));
+       fbi->regs = devm_ioremap_resource(&pdev->dev, res);
        if (fbi->regs == NULL) {
                dev_err(&pdev->dev, "Cannot map frame buffer registers\n");
                ret = -ENOMEM;
@@ -1049,11 +1042,9 @@ failed_cmap:
        dma_free_wc(&pdev->dev, fbi->map_size, info->screen_buffer,
                    fbi->map_dma);
 failed_map:
-       iounmap(fbi->regs);
 failed_ioremap:
 failed_getclock:
        release_mem_region(res->start, resource_size(res));
-failed_req:
 failed_of_parse:
        kfree(info->pseudo_palette);
 failed_init:
@@ -1065,11 +1056,6 @@ static int imxfb_remove(struct platform_device *pdev)
 {
        struct fb_info *info = platform_get_drvdata(pdev);
        struct imxfb_info *fbi = info->par;
-       struct resource *res;
-
-       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-       if (!res)
-               return -EINVAL;
 
        imxfb_disable_controller(fbi);
 
@@ -1077,8 +1063,6 @@ static int imxfb_remove(struct platform_device *pdev)
        fb_dealloc_cmap(&info->cmap);
        dma_free_wc(&pdev->dev, fbi->map_size, info->screen_buffer,
                    fbi->map_dma);
-       iounmap(fbi->regs);
-       release_mem_region(res->start, resource_size(res));
        kfree(info->pseudo_palette);
        framebuffer_release(info);