[PATCH] drm/bridge: dw-hdmi: fix EDID parsing

[luis.p.mendes@gmail.com (Luís Mendes)]

Hi,

I've just applied the referred individual patch to kernel-4.14-rc5 and
the EDID isn't loaded. dw-hdmi gets no firmware at all.

#cat /proc/cmdline
console=ttymxc0,115200 root=/dev/sda2 rw video=HDMI-A-1:1920x1080M at 60
drm.edid_firmware=edid/ktc_edid.bin dw_hdmi.dyndbg=+pfl cma=128M

#zcat /proc/config.gz  | grep EDID
CONFIG_DRM_LOAD_EDID_FIRMWARE=y
# CONFIG_FIRMWARE_EDID is not set

#cat /sys/class/drm/card1-HDMI-A-1/edid
<empty>

#dmesg
...
[    8.815238] imx-drm display-subsystem: bound imx-ipuv3-crtc.2 (ops
ipu_crtc_ops [imxdrm])
[    8.815555] imx-drm display-subsystem: bound imx-ipuv3-crtc.3 (ops
ipu_crtc_ops [imxdrm])
[    8.815832] imx-drm display-subsystem: bound imx-ipuv3-crtc.6 (ops
ipu_crtc_ops [imxdrm])
[    8.816073] imx-drm display-subsystem: bound imx-ipuv3-crtc.7 (ops
ipu_crtc_ops [imxdrm])
[    8.818243] dwhdmi-imx 120000.hdmi: Detected HDMI TX controller
v1.30a with HDCP (DWC HDMI 3D TX PHY)
[    8.821780] hdmi_set_clk_regenerator:521: dwhdmi-imx 120000.hdmi:
hdmi_set_clk_regenerator: fs=48000Hz ftdms=74.250MHz N=6144 cts=74250
[    8.831034] imx-drm display-subsystem: bound 120000.hdmi (ops
dw_hdmi_imx_ops [dw_hdmi_imx])
[    8.832218] [drm] Cannot find any crtc or sizes
[    8.839807] [drm] Initialized imx-drm 1.0.0 20120507 for
display-subsystem on minor 1

Regards,
Lu?s Mendes

On Thu, Nov 9, 2017 at 9:51 AM, Lu?s Mendes <luis.p.mendes@gmail.com> wrote:
> Hi everyone,
>
> I can try that patch and see if it fixes the problem.
> Give me a moment so that I can check how it goes.
>
> Lu?s
>
>
>
> On Thu, Nov 9, 2017 at 9:49 AM, Jani Nikula <jani.nikula@linux.intel.com>
> wrote:
>>
>> On Thu, 09 Nov 2017, Russell King - ARM Linux <linux@armlinux.org.uk>
>> wrote:
>> > On Thu, Nov 09, 2017 at 09:23:18AM +0100, Daniel Vetter wrote:
>> >> On Tue, Nov 07, 2017 at 11:27:21AM +0000, Russell King wrote:
>> >> > Parsing the EDID for HDMI and audio information in the get_modes()
>> >> > callback is incorrect - this only parses the EDID read from the
>> >> > connector, not any override or firmware provided EDID.
>> >> >
>> >> > The correct place to parse the EDID for these parameters is the
>> >> > fill_modes() callback, after we've called the helper.  Move the
>> >> > parsing
>> >> > there.  This caused problems for Lu?s Mendes.
>> >> >
>> >> > Cc: <stable@vger.kernel.org>
>> >> > Reported-by: Lu?s Mendes <luis.p.mendes@gmail.com>
>> >> > Tested-by: Lu?s Mendes <luis.p.mendes@gmail.com>
>> >> > Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
>> >> > ---
>> >> >  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 28
>> >> > ++++++++++++++++++++++++----
>> >> >  1 file changed, 24 insertions(+), 4 deletions(-)
>> >> >
>> >> > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> >> > b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> >> > index 9fe407f49986..2516a1c18a10 100644
>> >> > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> >> > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> >> > @@ -1905,10 +1905,7 @@ static int dw_hdmi_connector_get_modes(struct
>> >> > drm_connector *connector)
>> >> >            dev_dbg(hdmi->dev, "got edid: width[%d] x height[%d]\n",
>> >> >                    edid->width_cm, edid->height_cm);
>> >> >
>> >> > -          hdmi->sink_is_hdmi = drm_detect_hdmi_monitor(edid);
>> >> > -          hdmi->sink_has_audio = drm_detect_monitor_audio(edid);
>> >> >            drm_mode_connector_update_edid_property(connector, edid);
>> >> > -          cec_notifier_set_phys_addr_from_edid(hdmi->cec_notifier,
>> >> > edid);
>> >> >            ret = drm_add_edid_modes(connector, edid);
>> >> >            /* Store the ELD */
>> >> >            drm_edid_to_eld(connector, edid);
>> >> > @@ -1920,6 +1917,29 @@ static int dw_hdmi_connector_get_modes(struct
>> >> > drm_connector *connector)
>> >> >    return ret;
>> >> >  }
>> >> >
>> >> > +static int dw_hdmi_connector_fill_modes(struct drm_connector
>> >> > *connector,
>> >> > +                                  uint32_t maxX, uint32_t maxY)
>> >> > +{
>> >> > +  struct dw_hdmi *hdmi = container_of(connector, struct dw_hdmi,
>> >> > +                                      connector);
>> >> > +  int ret;
>> >> > +
>> >> > +  ret = drm_helper_probe_single_connector_modes(connector, maxX,
>> >> > maxY);
>> >> > +
>> >> > +  if (connector->edid_blob_ptr) {
>> >> > +          struct edid *edid = (void
>> >> > *)connector->edid_blob_ptr->data;
>> >> > +
>> >> > +          hdmi->sink_is_hdmi = drm_detect_hdmi_monitor(edid);
>> >> > +          hdmi->sink_has_audio = drm_detect_monitor_audio(edid);
>> >> > +          cec_notifier_set_phys_addr_from_edid(hdmi->cec_notifier,
>> >> > edid);
>> >> > +  } else {
>> >> > +          hdmi->sink_is_hdmi = false;
>> >> > +          hdmi->sink_has_audio = false;
>> >> > +  }
>> >> > +
>> >> > +  return ret;
>> >> > +}
>> >> > +
>> >> >  static void dw_hdmi_connector_force(struct drm_connector *connector)
>> >> >  {
>> >> >    struct dw_hdmi *hdmi = container_of(connector, struct dw_hdmi,
>> >> > @@ -1933,7 +1953,7 @@ static void dw_hdmi_connector_force(struct
>> >> > drm_connector *connector)
>> >> >  }
>> >> >
>> >> >  static const struct drm_connector_funcs dw_hdmi_connector_funcs = {
>> >> > -  .fill_modes = drm_helper_probe_single_connector_modes,
>> >> > +  .fill_modes = dw_hdmi_connector_fill_modes,
>> >>
>> >> Papering over helper functions shouldn't be necessary, except the
>> >> helper
>> >> functions not handling the override edid is a known issue. Jani Nikula
>> >> is
>> >> working on a proper fix, please coordinate with him.
>> >
>> > So, what you're basically saying is that fixing real bugs that affect
>> > users is not something that DRM people want.  That's fine, I'll ignore
>> > people who come to me for help with DRM bugs in future then because
>> > it's obviously a dead loss.
>>
>> We may already have fixed the bug in drm-next at the proper
>> layer. Please see my other mail.
>>
>> BR,
>> Jani.
>>
>> --
>> Jani Nikula, Intel Open Source Technology Center
>
>