diff mbox series

[6/8] fbdev: sm712fb: fix crashes and garbled display during DPMS modesetting.

Message ID 20190316222504.27170-7-tomli@tomli.me (mailing list archive)
State New, archived
Headers show
Series fbdev: sm712fb: fix a series of lockups, crashes and gliches. | expand

Commit Message

Yifeng Li March 16, 2019, 10:25 p.m. UTC 
On a Thinkpad s30 (Pentium III / i440MX, Lynx3DM), blanking the display
or starting the X server will crash and freeze the system, or garble the
display.

Experiments showed this problem can mostly be solved by adjusting the
order of register writes. Also, sm712fb failed to consider the difference
of clock frequency when unblanking the display, and programs the clock for
SM712 to SM720.

Fix them by adjusting the order of register writes, and adding an
additional check for SM720 for programming the clock frequency.

Signed-off-by: Yifeng Li <tomli@tomli.me>
Cc: stable@vger.kernel.org  # v4.4+
---
 drivers/video/fbdev/sm712fb.c | 64 +++++++++++++++++++++--------------
 1 file changed, 38 insertions(+), 26 deletions(-)

Comments

Sudip Mukherjee March 31, 2019, 12:20 p.m. UTC | #1 
On Sun, Mar 17, 2019 at 06:25:02AM +0800, Yifeng Li wrote:
> On a Thinkpad s30 (Pentium III / i440MX, Lynx3DM), blanking the display
> or starting the X server will crash and freeze the system, or garble the
> display.
> 
> Experiments showed this problem can mostly be solved by adjusting the
> order of register writes. Also, sm712fb failed to consider the difference
> of clock frequency when unblanking the display, and programs the clock for
> SM712 to SM720.
> 
> Fix them by adjusting the order of register writes, and adding an
> additional check for SM720 for programming the clock frequency.
> 
> Signed-off-by: Yifeng Li <tomli@tomli.me>
> Cc: stable@vger.kernel.org  # v4.4+

Tested-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>

--
Regards
Sudip
diff mbox series

Patch

diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c
index 52234c57be02..a40d0ae7cb66 100644
--- a/drivers/video/fbdev/sm712fb.c
+++ b/drivers/video/fbdev/sm712fb.c
@@ -827,67 +827,79 @@  static inline unsigned int chan_to_field(unsigned int chan,
 
 static int smtc_blank(int blank_mode, struct fb_info *info)
 {
+	struct smtcfb_info *sfb = info->par;
+
 	/* clear DPMS setting */
 	switch (blank_mode) {
 	case FB_BLANK_UNBLANK:
 		/* Screen On: HSync: On, VSync : On */
+
+		switch (sfb->chip_id) {
+		case 0x710:
+		case 0x712:
+			smtc_seqw(0x6a, 0x16);
+			smtc_seqw(0x6b, 0x02);
+		case 0x720:
+			smtc_seqw(0x6a, 0x0d);
+			smtc_seqw(0x6b, 0x02);
+			break;
+		}
+
+		smtc_seqw(0x23, (smtc_seqr(0x23) & (~0xc0)));
 		smtc_seqw(0x01, (smtc_seqr(0x01) & (~0x20)));
-		smtc_seqw(0x6a, 0x16);
-		smtc_seqw(0x6b, 0x02);
 		smtc_seqw(0x21, (smtc_seqr(0x21) & 0x77));
 		smtc_seqw(0x22, (smtc_seqr(0x22) & (~0x30)));
-		smtc_seqw(0x23, (smtc_seqr(0x23) & (~0xc0)));
-		smtc_seqw(0x24, (smtc_seqr(0x24) | 0x01));
 		smtc_seqw(0x31, (smtc_seqr(0x31) | 0x03));
+		smtc_seqw(0x24, (smtc_seqr(0x24) | 0x01));
 		break;
 	case FB_BLANK_NORMAL:
 		/* Screen Off: HSync: On, VSync : On   Soft blank */
+		smtc_seqw(0x24, (smtc_seqr(0x24) | 0x01));
+		smtc_seqw(0x31, ((smtc_seqr(0x31) & (~0x07)) | 0x00));
+		smtc_seqw(0x23, (smtc_seqr(0x23) & (~0xc0)));
 		smtc_seqw(0x01, (smtc_seqr(0x01) & (~0x20)));
+		smtc_seqw(0x22, (smtc_seqr(0x22) & (~0x30)));
 		smtc_seqw(0x6a, 0x16);
 		smtc_seqw(0x6b, 0x02);
-		smtc_seqw(0x22, (smtc_seqr(0x22) & (~0x30)));
-		smtc_seqw(0x23, (smtc_seqr(0x23) & (~0xc0)));
-		smtc_seqw(0x24, (smtc_seqr(0x24) | 0x01));
-		smtc_seqw(0x31, ((smtc_seqr(0x31) & (~0x07)) | 0x00));
 		break;
 	case FB_BLANK_VSYNC_SUSPEND:
 		/* Screen On: HSync: On, VSync : Off */
+		smtc_seqw(0x24, (smtc_seqr(0x24) & (~0x01)));
+		smtc_seqw(0x31, ((smtc_seqr(0x31) & (~0x07)) | 0x00));
+		smtc_seqw(0x23, ((smtc_seqr(0x23) & (~0xc0)) | 0x20));
 		smtc_seqw(0x01, (smtc_seqr(0x01) | 0x20));
-		smtc_seqw(0x20, (smtc_seqr(0x20) & (~0xB0)));
-		smtc_seqw(0x6a, 0x0c);
-		smtc_seqw(0x6b, 0x02);
 		smtc_seqw(0x21, (smtc_seqr(0x21) | 0x88));
+		smtc_seqw(0x20, (smtc_seqr(0x20) & (~0xB0)));
 		smtc_seqw(0x22, ((smtc_seqr(0x22) & (~0x30)) | 0x20));
-		smtc_seqw(0x23, ((smtc_seqr(0x23) & (~0xc0)) | 0x20));
-		smtc_seqw(0x24, (smtc_seqr(0x24) & (~0x01)));
-		smtc_seqw(0x31, ((smtc_seqr(0x31) & (~0x07)) | 0x00));
 		smtc_seqw(0x34, (smtc_seqr(0x34) | 0x80));
+		smtc_seqw(0x6a, 0x0c);
+		smtc_seqw(0x6b, 0x02);
 		break;
 	case FB_BLANK_HSYNC_SUSPEND:
 		/* Screen On: HSync: Off, VSync : On */
+		smtc_seqw(0x24, (smtc_seqr(0x24) & (~0x01)));
+		smtc_seqw(0x31, ((smtc_seqr(0x31) & (~0x07)) | 0x00));
+		smtc_seqw(0x23, ((smtc_seqr(0x23) & (~0xc0)) | 0xD8));
 		smtc_seqw(0x01, (smtc_seqr(0x01) | 0x20));
-		smtc_seqw(0x20, (smtc_seqr(0x20) & (~0xB0)));
-		smtc_seqw(0x6a, 0x0c);
-		smtc_seqw(0x6b, 0x02);
 		smtc_seqw(0x21, (smtc_seqr(0x21) | 0x88));
+		smtc_seqw(0x20, (smtc_seqr(0x20) & (~0xB0)));
 		smtc_seqw(0x22, ((smtc_seqr(0x22) & (~0x30)) | 0x10));
-		smtc_seqw(0x23, ((smtc_seqr(0x23) & (~0xc0)) | 0xD8));
-		smtc_seqw(0x24, (smtc_seqr(0x24) & (~0x01)));
-		smtc_seqw(0x31, ((smtc_seqr(0x31) & (~0x07)) | 0x00));
 		smtc_seqw(0x34, (smtc_seqr(0x34) | 0x80));
+		smtc_seqw(0x6a, 0x0c);
+		smtc_seqw(0x6b, 0x02);
 		break;
 	case FB_BLANK_POWERDOWN:
 		/* Screen On: HSync: Off, VSync : Off */
+		smtc_seqw(0x24, (smtc_seqr(0x24) & (~0x01)));
+		smtc_seqw(0x31, ((smtc_seqr(0x31) & (~0x07)) | 0x00));
+		smtc_seqw(0x23, ((smtc_seqr(0x23) & (~0xc0)) | 0xD8));
 		smtc_seqw(0x01, (smtc_seqr(0x01) | 0x20));
-		smtc_seqw(0x20, (smtc_seqr(0x20) & (~0xB0)));
-		smtc_seqw(0x6a, 0x0c);
-		smtc_seqw(0x6b, 0x02);
 		smtc_seqw(0x21, (smtc_seqr(0x21) | 0x88));
+		smtc_seqw(0x20, (smtc_seqr(0x20) & (~0xB0)));
 		smtc_seqw(0x22, ((smtc_seqr(0x22) & (~0x30)) | 0x30));
-		smtc_seqw(0x23, ((smtc_seqr(0x23) & (~0xc0)) | 0xD8));
-		smtc_seqw(0x24, (smtc_seqr(0x24) & (~0x01)));
-		smtc_seqw(0x31, ((smtc_seqr(0x31) & (~0x07)) | 0x00));
 		smtc_seqw(0x34, (smtc_seqr(0x34) | 0x80));
+		smtc_seqw(0x6a, 0x0c);
+		smtc_seqw(0x6b, 0x02);
 		break;
 	default:
 		return -EINVAL;