[PATCH 4.9 108/212] video: fbdev: sm712fb: fix an issue about iounmap for a wrong address

[Greg Kroah-Hartman]

From: Dejin Zheng <zhengdejin5@xxxxxxxxx>

[ Upstream commit 98bd4f72988646c35569e1e838c0ab80d06c77f6 ]

the sfb->fb->screen_base is not save the value get by iounmap() when
the chip id is 0x720. so iounmap() for address sfb->fb->screen_base
is not right.

Fixes: 1461d6672864854 ("staging: sm7xxfb: merge sm712fb with fbdev")
Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Cc: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
Cc: Teddy Wang <teddy.wang@xxxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dejin Zheng <zhengdejin5@xxxxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20200422160719.27763-1-zhengdejin5@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/video/fbdev/sm712fb.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c
index 0d92ff366a7b7..17efcdd4dc99b 100644
--- a/drivers/video/fbdev/sm712fb.c
+++ b/drivers/video/fbdev/sm712fb.c
@@ -1428,6 +1428,8 @@ static int smtc_map_smem(struct smtcfb_info *sfb,
 static void smtc_unmap_smem(struct smtcfb_info *sfb)
 {
 	if (sfb && sfb->fb->screen_base) {
+		if (sfb->chip_id == 0x720)
+			sfb->fb->screen_base -= 0x00200000;
 		iounmap(sfb->fb->screen_base);
 		sfb->fb->screen_base = NULL;
 	}
-- 
2.25.1