Re: [PATCH v1 2/4] drm: mxsfb: Allow optional LCDIF interface format override

[Francesco Dolcini <francesco@dolcini.it>]

Hello Marco,

On Tue, Jul 21, 2026 at 10:52:37AM +0200, Marco Felsch wrote:
> On 26-07-17, Francesco Dolcini wrote:
> > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > 
> > LCDIF programs LCD_DATABUS_WIDTH from the selected media bus format. The
> > format reported by the downstream panel or bridge describes the display
> > input, but it does not describe how the LCDIF data pins are physically
> > wired on the board.
> > 
> > These can differ. For example, a 16-bit LCDIF bus can be connected to a
> > 24-bit display by wiring the available color bits to the corresponding
> > display inputs. In that case, using the display's 24-bit format to
> > configure LCDIF selects the wrong data-bus mode and changes the assignment
> > of color bits on the LCD_DATA pins.
> > 
> > Read the optional interface-pix-fmt property from the LCDIF node and use
> > it to select the media bus format used to configure LCDIF. This allows
> > the LCDIF bus mode to describe the physical interface independently of
> > the downstream display format.
> > 
> > When the optional property is absent, continue using the format reported
> > by the downstream display device, preserving the existing behavior.
> > 
> > This follows the same approach already implemented in
> > drivers/gpu/drm/imx/ipuv3/parallel-display.c.
> 
> According the driver comment, this is a legacy property. If you just
> want to limit the physical bus width you could use the common of-graph
> endpoint bus-width property.

Yes, I will change to that. Thanks for the feedback.

Francesco