[Intel-gfx] [PATCH v2 7/7] drm/i915: Check pixel rate for DP to VGA dongle
Daniel Vetter
daniel at ffwll.ch
Tue May 17 06:45:07 UTC 2016
On Mon, May 16, 2016 at 04:19:33PM +0300, Mika Kahola wrote:
> Prep work to improve DP branch device handling.
>
> Filter out a mode that exceeds the max pixel rate setting
> for DP to VGA dongle. This is defined in DPCD register 0x81
> if detailed cap info i.e. info field is 4 bytes long and
> it is available for DP downstream port.
>
> The register defines the pixel rate divided by 8 in MP/s.
>
> v2: DPCD read outs and computation moved to drm (Ville, Daniel)
>
> Signed-off-by: Mika Kahola <mika.kahola at intel.com>
> ---
> drivers/gpu/drm/i915/intel_dp.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 3633002..5ec6287 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -201,6 +201,12 @@ intel_dp_mode_valid(struct drm_connector *connector,
> int max_rate, mode_rate, max_lanes, max_link_clock;
> int max_dotclk = to_i915(connector->dev)->max_dotclk_freq;
>
> + /* DP to VGA dongle may define max pixel rate in DPCD */
> + if (intel_dp->bd.present &&
> + (intel_dp->bd.type & DP_DS_PORT_TYPE_VGA) &&
> + (intel_dp->bd.dfp.vga.dot_clk > 0))
> + max_dotclk = min(max_dotclk, intel_dp->bd.dfp.vga.dot_clk);
I think this is rendering the helpers a bit pointless if you have to dig
around so much in internals. drm_dp_helper_max_sink_dotclock(), and then
we have a place to put more of that stuff?
-Daniel
> +
> if (is_edp(intel_dp) && fixed_mode) {
> if (mode->hdisplay > fixed_mode->hdisplay)
> return MODE_PANEL;
> @@ -4575,6 +4581,7 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
> struct drm_i915_private *dev_priv = dev->dev_private;
> enum intel_display_power_domain power_domain;
> enum irqreturn ret = IRQ_NONE;
> + int err;
>
> if (intel_dig_port->base.type != INTEL_OUTPUT_EDP &&
> intel_dig_port->base.type != INTEL_OUTPUT_HDMI)
> @@ -4599,6 +4606,10 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
> power_domain = intel_display_port_aux_power_domain(intel_encoder);
> intel_display_power_get(dev_priv, power_domain);
>
> + err = drm_dp_bd(&intel_dp->aux, &intel_dp->bd);
> + if (err < 0)
> + DRM_DEBUG_KMS("error reading DPCD[0x80] for DP branch device\n");
> +
> if (long_hpd) {
> /* indicate that we need to restart link training */
> intel_dp->train_set_valid = false;
> --
> 1.9.1
>
> _______________________________________________
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> Intel-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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