From: René Rebe <rene@exactco.de>
Date: Thu, 20 Nov 2025 13:24:00 +0000 (+0100)
Subject: fbdev: tcx.c fix mem_map to correct smem_start offset
X-Git-Tag: v5.15.198~157
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c3548c44c3c2c517926a1844692acb8c85624a75;p=thirdparty%2Fkernel%2Fstable.git

fbdev: tcx.c fix mem_map to correct smem_start offset

commit 35fa2b4bf96415b88d7edaa5cf8af5185d9ce76e upstream.

403ae52ac047 ("sparc: fix drivers/video/tcx.c warning") changed the
physbase initializing breaking the user-space mmap, e.g. for Xorg
entirely.

Fix fbdev mmap table so the sbus mmap helper work correctly, and
not try to map vastly (physbase) offset memory.

Fixes: 403ae52ac047 ("sparc: fix drivers/video/tcx.c warning")
Cc: <stable@vger.kernel.org>
Signed-off-by: René Rebe <rene@exactco.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/video/fbdev/tcx.c b/drivers/video/fbdev/tcx.c
index 1638a40fed225..ee8049344c309 100644
--- a/drivers/video/fbdev/tcx.c
+++ b/drivers/video/fbdev/tcx.c
@@ -436,7 +436,7 @@ static int tcx_probe(struct platform_device *op)
 			j = i;
 			break;
 		}
-		par->mmap_map[i].poff = op->resource[j].start;
+		par->mmap_map[i].poff = op->resource[j].start - info->fix.smem_start;
 	}
 
 	info->flags = FBINFO_DEFAULT;