From fcac71697a15061ebf2694d4258bde5be6d85a72 Mon Sep 17 00:00:00 2001 From: Yifeng Li Date: Tue, 2 Apr 2019 17:14:10 +0200 Subject: [PATCH] fbdev: sm712fb: fix memory frequency by avoiding a switch/case fallthrough commit 9dc20113988b9a75ea6b3abd68dc45e2d73ccdab upstream. A fallthrough in switch/case was introduced in f627caf55b8e ("fbdev: sm712fb: fix crashes and garbled display during DPMS modesetting"), due to my copy-paste error, which would cause the memory clock frequency for SM720 to be programmed to SM712. Since it only reprograms the clock to a different frequency, it's only a benign issue without visible side-effect, so it also evaded Sudip Mukherjee's code review and regression tests. scripts/checkpatch.pl also failed to discover the issue, possibly due to nested switch statements. This issue was found by Stephen Rothwell by building linux-next with -Wimplicit-fallthrough. Reported-by: Stephen Rothwell Fixes: f627caf55b8e ("fbdev: sm712fb: fix crashes and garbled display during DPMS modesetting") Signed-off-by: Yifeng Li Cc: Sudip Mukherjee Cc: "Gustavo A. R. Silva" Cc: Kees Cook Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbdev/sm712fb.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c index 1e2503b..f1dcc67 100644 --- a/drivers/video/fbdev/sm712fb.c +++ b/drivers/video/fbdev/sm712fb.c @@ -898,6 +898,7 @@ static int smtc_blank(int blank_mode, struct fb_info *info) case 0x712: smtc_seqw(0x6a, 0x16); smtc_seqw(0x6b, 0x02); + break; case 0x720: smtc_seqw(0x6a, 0x0d); smtc_seqw(0x6b, 0x02); -- 2.7.4