[uClinux-dev] [PATCH 1/2] mtd: fix wrong usage of ioremap_nocache() in uclinux.c map driver

gerg at snapgear.com gerg at snapgear.com
Thu May 10 02:55:28 EDT 2012


From: Greg Ungerer <gerg at uclinux.org>

The uclinux.c mapping driver uses ioremap_nocache() to map its physical
mapping address to a system virtual address. Problem is that the region
it is mapping is not device memory. It is ordinary system RAM. On most
non-MMU systems this doesn't matter, and the mapping is always a 1:1
translation of the address.

But if we want to use the uclinux.c mapping driver on real MMU enabled
systems we should be using phys_to_virt() for the translation, since that
is really what we are doing. So change it to do that.

Signed-off-by: Greg Ungerer <gerg at uclinux.org>
---
 drivers/mtd/maps/uclinux.c |    9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/maps/uclinux.c b/drivers/mtd/maps/uclinux.c
index cfff454..6d43c75 100644
--- a/drivers/mtd/maps/uclinux.c
+++ b/drivers/mtd/maps/uclinux.c
@@ -68,10 +68,10 @@ static int __init uclinux_mtd_init(void)
 	printk("uclinux[mtd]: RAM probe address=0x%x size=0x%x\n",
 	       	(int) mapp->phys, (int) mapp->size);
 
-	mapp->virt = ioremap_nocache(mapp->phys, mapp->size);
+	mapp->virt = phys_to_virt(mapp->phys);
 
 	if (mapp->virt == 0) {
-		printk("uclinux[mtd]: ioremap_nocache() failed\n");
+		printk("uclinux[mtd]: no virtual mapping?\n");
 		return(-EIO);
 	}
 
@@ -80,7 +80,6 @@ static int __init uclinux_mtd_init(void)
 	mtd = do_map_probe("map_ram", mapp);
 	if (!mtd) {
 		printk("uclinux[mtd]: failed to find a mapping?\n");
-		iounmap(mapp->virt);
 		return(-ENXIO);
 	}
 
@@ -103,10 +102,8 @@ static void __exit uclinux_mtd_cleanup(void)
 		map_destroy(uclinux_ram_mtdinfo);
 		uclinux_ram_mtdinfo = NULL;
 	}
-	if (uclinux_ram_map.virt) {
-		iounmap((void *) uclinux_ram_map.virt);
+	if (uclinux_ram_map.virt)
 		uclinux_ram_map.virt = 0;
-	}
 }
 
 /****************************************************************************/
-- 
1.7.0.4




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