Re: [v2,03/10] drm/sun4i: Protect the TCON pixel clocks

[Giulio Benetti]

Il 21/02/2018 10:20, Maxime Ripard ha scritto:
> From: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
>
> Both TCON clocks are very sensitive to clock changes, since any change
> might lead to improper timings.
>
> Make sure our rate is never changed.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Tested-by: Giulio Benetti <giulio.benetti@xxxxxxxxxxxxxxxx>

Tested on A20-LiNova1-4_3i-ctp with Mali r6p2 installed.
Before Mali changed dotclock, now it doesn't anymore.

> ---
>   drivers/gpu/drm/sun4i/sun4i_tcon.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> index b73acab74867..cbe87cee13d1 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> @@ -261,7 +261,7 @@ static void sun4i_tcon0_mode_set_common(struct sun4i_tcon *tcon,
>   					const struct drm_display_mode *mode)
>   {
>   	/* Configure the dot clock */
> -	clk_set_rate(tcon->dclk, mode->crtc_clock * 1000);
> +	clk_set_rate_exclusive(tcon->dclk, mode->crtc_clock * 1000);
>   
>   	/* Set the resolution */
>   	regmap_write(tcon->regs, SUN4I_TCON0_BASIC0_REG,
> @@ -419,7 +419,7 @@ static void sun4i_tcon1_mode_set(struct sun4i_tcon *tcon,
>   	WARN_ON(!tcon->quirks->has_channel_1);
>   
>   	/* Configure the dot clock */
> -	clk_set_rate(tcon->sclk1, mode->crtc_clock * 1000);
> +	clk_set_rate_exclusive(tcon->sclk1, mode->crtc_clock * 1000);
>   
>   	/* Adjust clock delay */
>   	clk_delay = sun4i_tcon_get_clk_delay(mode, 1);