[PATCH 1/3] drm: bridge: icn6211: Only warn on invalid chip IDs

[Jagan Teki]

Hi Brandon,

On Wed, Apr 19, 2023 at 12:43 AM Marek Vasut <marex at denx.de> wrote:
>
> On 4/18/23 15:42, Jagan Teki wrote:
> > On Tue, Apr 18, 2023 at 5:52 PM Brandon Cheo Fusi
> > <fusibrandon13 at gmail.com> wrote:
> >>
> >> Avoid aborting chip configuration after reading invalid IDs and
> >> instead issue a warning. I have a bunch of these chips and they all
> >> report "Vendor=0x00 Device=0x00:0x00 Version=0x00" but are successfully
> >> configured and go on to work just fine.
> >>
> >> Signed-off-by: Brandon Cheo Fusi <fusibrandon13 at gmail.com>
> >> ---
> >>   drivers/gpu/drm/bridge/chipone-icn6211.c | 3 +--
> >>   1 file changed, 1 insertion(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c
> >> index 0e37840cd..39de9a7c7 100644
> >> --- a/drivers/gpu/drm/bridge/chipone-icn6211.c
> >> +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c
> >> @@ -361,8 +361,7 @@ static void chipone_atomic_enable(struct drm_bridge *bridge,
> >>                  id[0], id[1], id[2], id[3]);
> >>
> >>          if (id[0] != 0xc1 || id[1] != 0x62 || id[2] != 0x11) {
> >> -               dev_dbg(icn->dev, "Invalid Chip IDs, aborting configuration\n");
> >> -               return;
> >> +               dev_warn(icn->dev, "Invalid Chip IDs, configuration may fail\n");
> >
> > Did you test I2C-Configured ICN6211 or non-I2C-Configured? if it's
> > later then better to fix a valid ID for it or if it doesn't support ID
> > then a handle via quirk would be a proper solution.
>
> The ICN6211 should always be accessible via either option. If the ID
> readout does not work, the bug is likely in broken DSI command mode on
> whatever DSI host is used, or, the ICN6211 clock are misconfigured.

Look like Marek was correct, please check your DSI host->transfer
support MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM if it is implemented
then the readid would pass.

Jagan.