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[2/4,resend,#2] tridentfb: Fix set_lwidth on TGUI9440 and CYBER9320

Message ID 1440445048-24694-2-git-send-email-linux@rainbow-software.org (mailing list archive)
State New, archived
Headers show

Commit Message

Ondrej Zary Aug. 24, 2015, 7:37 p.m. UTC
According to X.Org driver, chips older than TGUI9660 have only 1 width bit
in AddColReg. Touching the 2nd one causes I2C/DDC to fail on TGUI9440.

Set only 1 bit of width in AddColReg on TGUI9440 and CYBER9320.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
---
 drivers/video/fbdev/tridentfb.c |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

Comments

Tomi Valkeinen Sept. 24, 2015, 11:07 a.m. UTC | #1
On 24/08/15 22:37, Ondrej Zary wrote:
> According to X.Org driver, chips older than TGUI9660 have only 1 width bit
> in AddColReg. Touching the 2nd one causes I2C/DDC to fail on TGUI9440.
> 
> Set only 1 bit of width in AddColReg on TGUI9440 and CYBER9320.
> 
> Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
> ---
>  drivers/video/fbdev/tridentfb.c |   10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/video/fbdev/tridentfb.c b/drivers/video/fbdev/tridentfb.c
> index 7429713..01b43e9 100644
> --- a/drivers/video/fbdev/tridentfb.c
> +++ b/drivers/video/fbdev/tridentfb.c
> @@ -673,8 +673,14 @@ static int get_nativex(struct tridentfb_par *par)
>  static inline void set_lwidth(struct tridentfb_par *par, int width)
>  {
>  	write3X4(par, VGA_CRTC_OFFSET, width & 0xFF);
> -	write3X4(par, AddColReg,
> -		 (read3X4(par, AddColReg) & 0xCF) | ((width & 0x300) >> 4));
> +	/* chips older than TGUI9660 have only 1 width bit in AddColReg */
> +	/* touching the other one breaks I2C/DDC */
> +	if (par->chip_id == TGUI9440 || par->chip_id == CYBER9320)
> +		write3X4(par, AddColReg,
> +		     (read3X4(par, AddColReg) & 0xEF) | ((width & 0x100) >> 4));
> +	else
> +		write3X4(par, AddColReg,
> +		     (read3X4(par, AddColReg) & 0xCF) | ((width & 0x300) >> 4));
>  }
>  
>  /* For resolutions smaller than FP resolution stretch */
> 

Thanks, queued for 4.3 fixes.

Tomi
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Patch

diff --git a/drivers/video/fbdev/tridentfb.c b/drivers/video/fbdev/tridentfb.c
index 7429713..01b43e9 100644
--- a/drivers/video/fbdev/tridentfb.c
+++ b/drivers/video/fbdev/tridentfb.c
@@ -673,8 +673,14 @@  static int get_nativex(struct tridentfb_par *par)
 static inline void set_lwidth(struct tridentfb_par *par, int width)
 {
 	write3X4(par, VGA_CRTC_OFFSET, width & 0xFF);
-	write3X4(par, AddColReg,
-		 (read3X4(par, AddColReg) & 0xCF) | ((width & 0x300) >> 4));
+	/* chips older than TGUI9660 have only 1 width bit in AddColReg */
+	/* touching the other one breaks I2C/DDC */
+	if (par->chip_id == TGUI9440 || par->chip_id == CYBER9320)
+		write3X4(par, AddColReg,
+		     (read3X4(par, AddColReg) & 0xEF) | ((width & 0x100) >> 4));
+	else
+		write3X4(par, AddColReg,
+		     (read3X4(par, AddColReg) & 0xCF) | ((width & 0x300) >> 4));
 }
 
 /* For resolutions smaller than FP resolution stretch */