[PATCH] fbdev: xilinxfb: request memory region before mapping framebuffer
STALE276d
From: <hidden>
Date: 2025-12-16 08:05:37
Also in:
dri-devel
Subsystem:
framebuffer layer, the rest · Maintainers:
Helge Deller, Linus Torvalds
From: DiviyamPathak <redacted> The xilinxfb driver maps a physical framebuffer address with ioremap() without first reserving the memory region. This can conflict with other drivers accessing the same resource. Request the memory region with devm_request_mem_region() before mapping the framebuffer and use managed mappings for proper lifetime handling. This addresses the fbdev TODO about requesting memory regions and avoids potential resource conflicts. Signed-off-by: DiviyamPathak <redacted> --- drivers/video/fbdev/xilinxfb.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-)
diff --git a/drivers/video/fbdev/xilinxfb.c b/drivers/video/fbdev/xilinxfb.c
index 0a6e05cd155a..f18437490de8 100644
--- a/drivers/video/fbdev/xilinxfb.c
+++ b/drivers/video/fbdev/xilinxfb.c@@ -280,19 +280,27 @@ static int xilinxfb_assign(struct platform_device *pdev, /* Allocate the framebuffer memory */ if (pdata->fb_phys) { drvdata->fb_phys = pdata->fb_phys; - drvdata->fb_virt = ioremap(pdata->fb_phys, fbsize); + /* Request the memory region before mapping */ + if (!devm_request_mem_region(dev, pdata->fb_phys, fbsize, + DRIVER_NAME)) { + dev_err(dev, "Cannot request framebuffer memory region\n"); + return -EBUSY; + } + drvdata->fb_virt = devm_ioremap(dev, pdata->fb_phys, fbsize); + if (!drvdata->fb_virt) { + dev_err(dev, "Could not map framebuffer memory\n"); + return -ENOMEM; + } } else { drvdata->fb_alloced = 1; drvdata->fb_virt = dma_alloc_coherent(dev, PAGE_ALIGN(fbsize), - &drvdata->fb_phys, - GFP_KERNEL); - } - - if (!drvdata->fb_virt) { - dev_err(dev, "Could not allocate frame buffer memory\n"); - return -ENOMEM; + &drvdata->fb_phys, + GFP_KERNEL); + if (!drvdata->fb_virt) { + dev_err(dev, "Could not allocate frame buffer memory\n"); + return -ENOMEM; + } } - /* Clear (turn to black) the framebuffer */ memset_io((void __iomem *)drvdata->fb_virt, 0, fbsize);
@@ -362,8 +370,6 @@ static int xilinxfb_assign(struct platform_device *pdev, if (drvdata->fb_alloced) dma_free_coherent(dev, PAGE_ALIGN(fbsize), drvdata->fb_virt, drvdata->fb_phys); - else - iounmap(drvdata->fb_virt); /* Turn off the display */ xilinx_fb_out32(drvdata, REG_CTRL, 0);
@@ -386,8 +392,6 @@ static void xilinxfb_release(struct device *dev) if (drvdata->fb_alloced) dma_free_coherent(dev, PAGE_ALIGN(drvdata->info.fix.smem_len), drvdata->fb_virt, drvdata->fb_phys); - else - iounmap(drvdata->fb_virt); /* Turn off the display */ xilinx_fb_out32(drvdata, REG_CTRL, 0);
--
2.43.0