2014-01-09 11:11:56

by Jean-Francois Moine

Subject: [PATCH v2 17/28] drm/i2c: tda998x: set the repeat PLL value in range 0..3

Signed-off-by: Jean-Francois Moine <[email protected]>
---
drivers/gpu/drm/i2c/tda998x_drv.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c
index f60aef9..8a7d8a2 100644
--- a/drivers/gpu/drm/i2c/tda998x_drv.c
+++ b/drivers/gpu/drm/i2c/tda998x_drv.c
@@ -220,7 +220,7 @@ struct tda998x_priv {
# define PLL_SERIAL_1_SRL_IZ(x) (((x) & 3) << 1)
# define PLL_SERIAL_1_SRL_MAN_IZ (1 << 6)
#define REG_PLL_SERIAL_2 REG(0x02, 0x01) /* read/write */
-# define PLL_SERIAL_2_SRL_NOSC(x) (((x) & 3) << 0)
+# define PLL_SERIAL_2_SRL_NOSC(x) ((x) << 0)
# define PLL_SERIAL_2_SRL_PR(x) (((x) & 0xf) << 4)
#define REG_PLL_SERIAL_3 REG(0x02, 0x02) /* read/write */
# define PLL_SERIAL_3_SRL_CCIR (1 << 0)
@@ -972,6 +972,11 @@ tda998x_encoder_mode_set(struct drm_encoder *encoder,
}

div = 148500 / mode->clock;
+ if (div != 0) {
+ div--;
+ if (div > 3)
+ div = 3;
+ }

/* mute the audio FIFO: */
reg_set(priv, REG_AIP_CNTRL_0, AIP_CNTRL_0_RST_FIFO);
--
Ken ar c'hentañ | ** Breizh ha Linux atav! **
Jef | http://moinejf.free.fr/

2014-01-11 18:26:12

by Russell King - ARM Linux

Subject: Re: [PATCH v2 17/28] drm/i2c: tda998x: set the repeat PLL value in range 0..3

On Thu, Jan 09, 2014 at 12:05:13PM +0100, Jean-Francois Moine wrote:
>
> Signed-off-by: Jean-Francois Moine <[email protected]>
> ---
> drivers/gpu/drm/i2c/tda998x_drv.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c
> index f60aef9..8a7d8a2 100644
> --- a/drivers/gpu/drm/i2c/tda998x_drv.c
> +++ b/drivers/gpu/drm/i2c/tda998x_drv.c
> @@ -220,7 +220,7 @@ struct tda998x_priv {
> # define PLL_SERIAL_1_SRL_IZ(x) (((x) & 3) << 1)
> # define PLL_SERIAL_1_SRL_MAN_IZ (1 << 6)
> #define REG_PLL_SERIAL_2 REG(0x02, 0x01) /* read/write */
> -# define PLL_SERIAL_2_SRL_NOSC(x) (((x) & 3) << 0)
> +# define PLL_SERIAL_2_SRL_NOSC(x) ((x) << 0)
> # define PLL_SERIAL_2_SRL_PR(x) (((x) & 0xf) << 4)
> #define REG_PLL_SERIAL_3 REG(0x02, 0x02) /* read/write */
> # define PLL_SERIAL_3_SRL_CCIR (1 << 0)
> @@ -972,6 +972,11 @@ tda998x_encoder_mode_set(struct drm_encoder *encoder,
> }
>
> div = 148500 / mode->clock;
> + if (div != 0) {
> + div--;
> + if (div > 3)
> + div = 3;
> + }

As the driver currently stands, we know that the clock divider works for
the lower resolution modes. So, as things stand, for 74.25MHz modes,
we get a divisor of one.

Your patch changes this, the divider becomes zero. I wonder whether
you've tested 720p modes at all with this?

--
FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation
in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad.
Estimate before purchase was "up to 13.2Mbit".

2014-01-13 15:38:12

by Jean-Francois Moine

Subject: Re: [PATCH v2 17/28] drm/i2c: tda998x: set the repeat PLL value in range 0..3

On Sat, 11 Jan 2014 18:26:02 +0000
Russell King - ARM Linux <[email protected]> wrote:

> > div = 148500 / mode->clock;
> > + if (div != 0) {
> > + div--;
> > + if (div > 3)
> > + div = 3;
> > + }
>
> As the driver currently stands, we know that the clock divider works for
> the lower resolution modes. So, as things stand, for 74.25MHz modes,
> we get a divisor of one.
>
> Your patch changes this, the divider becomes zero. I wonder whether
> you've tested 720p modes at all with this?

In 720p, the divider becomes (148500 / 74250 - 1) = 1 and this mode
works fine.

--
Ken ar c'hentañ | ** Breizh ha Linux atav! **
Jef | http://moinejf.free.fr/