Re: [RFC PATCH v2 1/2] drm/bridge: ti-sn65dsi86: fetch bpc using drm_atomic_state

[Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>]

On 11/07/2022 12:10, Sam Ravnborg wrote:
> Hi Dmitry,
>
> On Mon, Jul 11, 2022 at 10:37:32AM +0300, Dmitry Baryshkov wrote:
> > Rather than reading the pdata->connector directly, fetch the connector
> > using drm_atomic_state. This allows us to make pdata->connector optional
> > (and thus supporting DRM_BRIDGE_ATTACH_NO_CONNECTOR).
> >
> > Reviewed-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/bridge/ti-sn65dsi86.c | 22 ++++++++++++++++------
> >   1 file changed, 16 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> > index d6dd4d99a229..b1b6ed3a8acc 100644
> > --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> > @@ -779,9 +779,9 @@ static void ti_sn_bridge_set_dsi_rate(struct ti_sn65dsi86 *pdata)
> >   	regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
> >   }
> >   
> > -static unsigned int ti_sn_bridge_get_bpp(struct ti_sn65dsi86 *pdata)
> > +static unsigned int ti_sn_bridge_get_bpp(struct drm_connector *connector)
> >   {
> > -	if (pdata->connector->display_info.bpc <= 6)
> > +	if (connector->display_info.bpc <= 6)
> >   		return 18;
> >   	else
> >   		return 24;
> > @@ -796,7 +796,7 @@ static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
> >   	0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
> >   };
> >   
> > -static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn65dsi86 *pdata)
> > +static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn65dsi86 *pdata, unsigned int bpp)
> >   {
> >   	unsigned int bit_rate_khz, dp_rate_mhz;
> >   	unsigned int i;
> > @@ -804,7 +804,7 @@ static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn65dsi86 *pdata)
> >   		&pdata->bridge.encoder->crtc->state->adjusted_mode;
> >   
> >   	/* Calculate minimum bit rate based on our pixel clock. */
> > -	bit_rate_khz = mode->clock * ti_sn_bridge_get_bpp(pdata);
> > +	bit_rate_khz = mode->clock * bpp;
> >   
> >   	/* Calculate minimum DP data rate, taking 80% as per DP spec */
> >   	dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM,
> > @@ -1016,12 +1016,21 @@ static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
> >   				       struct drm_bridge_state *old_bridge_state)
> >   {
> >   	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
> > +	struct drm_connector *connector;
> >   	const char *last_err_str = "No supported DP rate";
> >   	unsigned int valid_rates;
> >   	int dp_rate_idx;
> >   	unsigned int val;
> >   	int ret = -EINVAL;
> >   	int max_dp_lanes;
> > +	unsigned int bpp;
> > +
> > +	connector = drm_atomic_get_new_connector_for_encoder(old_bridge_state->base.state,
> > +							     bridge->encoder);
> > +	if (!connector) {
> > +		DRM_DEV_ERROR_RATELIMITED(pdata->dev, "Could not get the connector\n");
>
>  From the documentation of DRM_DEV_ERROR_RATELIMITED:
>   * NOTE: this is deprecated in favor of drm_err_ratelimited() or
>   * dev_err_ratelimited().
>
> Can you fix this, so we do not introduce deprecated functions/macros.

Ack. I hesitated between the DRM_DEV and dev_ functions, but decided to 
use the family that was used by the rest of the driver. Will change this 
call to the dev_err in v3.

> 	Sam
>
>
> > +		return;
> > +	}
> >   
> >   	max_dp_lanes = ti_sn_get_max_lanes(pdata);
> >   	pdata->dp_lanes = min(pdata->dp_lanes, max_dp_lanes);
> > @@ -1047,8 +1056,9 @@ static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
> >   	drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET,
> >   			   DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
> >   
> > +	bpp = ti_sn_bridge_get_bpp(connector);
> >   	/* Set the DP output format (18 bpp or 24 bpp) */
> > -	val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0;
> > +	val = bpp == 18 ? BPP_18_RGB : 0;
> >   	regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
> >   
> >   	/* DP lane config */
> > @@ -1059,7 +1069,7 @@ static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
> >   	valid_rates = ti_sn_bridge_read_valid_rates(pdata);
> >   
> >   	/* Train until we run out of rates */
> > -	for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata);
> > +	for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata, bpp);
> >   	     dp_rate_idx < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
> >   	     dp_rate_idx++) {
> >   		if (!(valid_rates & BIT(dp_rate_idx)))
> > --
> > 2.35.1


--
With best wishes
Dmitry