[PATCH] fbdev: sh7760fb: document fallthrough cases

Fix fallthrough warnings in sh776fb.c:

../drivers/video/fbdev/sh7760fb.c: In function 'sh7760fb_get_color_info':
../drivers/video/fbdev/sh7760fb.c:138:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
  138 |                 lgray = 1;
../drivers/video/fbdev/sh7760fb.c:143:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
  143 |                 lgray = 1;

Just document the current state of code execution/flow.

Fixes: 4a25e41831ee ("video: sh7760fb: SH7760/SH7763 LCDC framebuffer driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Nobuhiro Iwamatsu <redacted>
Cc: Manuel Lauss <redacted>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: linux-sh@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
---
 drivers/video/fbdev/sh7760fb.c |    2 ++
 1 file changed, 2 insertions(+)

--- linux-next-20211112.orig/drivers/video/fbdev/sh7760fb.c
+++ linux-next-20211112/drivers/video/fbdev/sh7760fb.c

@@ -136,11 +136,13 @@ static int sh7760fb_get_color_info(struc
 		break;
 	case LDDFR_4BPP_MONO:
 		lgray = 1;
+		fallthrough;
 	case LDDFR_4BPP:
 		lbpp = 4;
 		break;
 	case LDDFR_6BPP_MONO:
 		lgray = 1;
+		fallthrough;
 	case LDDFR_8BPP:
 		lbpp = 8;
 		break;

On Sun, Nov 14, 2021 at 10:32:57PM -0800, Randy Dunlap wrote:

Fix fallthrough warnings in sh776fb.c:

../drivers/video/fbdev/sh7760fb.c: In function 'sh7760fb_get_color_info':
../drivers/video/fbdev/sh7760fb.c:138:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
  138 |                 lgray = 1;
../drivers/video/fbdev/sh7760fb.c:143:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
  143 |                 lgray = 1;

Just document the current state of code execution/flow.

Fixes: 4a25e41831ee ("video: sh7760fb: SH7760/SH7763 LCDC framebuffer driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Nobuhiro Iwamatsu <redacted>
Cc: Manuel Lauss <redacted>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: linux-sh@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks, Randy.
--
Gustavo

On Mon, Nov 15, 2021 at 7:33 AM Randy Dunlap [off-list ref] wrote:

Fix fallthrough warnings in sh776fb.c:

../drivers/video/fbdev/sh7760fb.c: In function 'sh7760fb_get_color_info':
../drivers/video/fbdev/sh7760fb.c:138:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
  138 |                 lgray = 1;
../drivers/video/fbdev/sh7760fb.c:143:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
  143 |                 lgray = 1;

Just document the current state of code execution/flow.

Fixes: 4a25e41831ee ("video: sh7760fb: SH7760/SH7763 LCDC framebuffer driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>

Section 30.4.4 ("Data Format") of the SH7760 Group Hardware
Manual confirms fall-through is appropriate here (especially for
the odd 6 bpp mode).

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

On Mon, Nov 15, 2021 at 09:35:09AM +0100, Geert Uytterhoeven wrote:

On Mon, Nov 15, 2021 at 7:33 AM Randy Dunlap [off-list ref] wrote:

quoted

Fix fallthrough warnings in sh776fb.c:

../drivers/video/fbdev/sh7760fb.c: In function 'sh7760fb_get_color_info':
../drivers/video/fbdev/sh7760fb.c:138:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
  138 |                 lgray = 1;
../drivers/video/fbdev/sh7760fb.c:143:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
  143 |                 lgray = 1;

Just document the current state of code execution/flow.

Fixes: 4a25e41831ee ("video: sh7760fb: SH7760/SH7763 LCDC framebuffer driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>

Section 30.4.4 ("Data Format") of the SH7760 Group Hardware
Manual confirms fall-through is appropriate here (especially for
the odd 6 bpp mode).

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

I'm taking this in my -next tree[1].

Thanks
--
Gustavo

[1] https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/log/?h=for-next/kspp-misc-fixes