On 17/11/2022 15:59, Mark Brown wrote:
So this is an issue in the MIPI DBI code where the interpretation of
the buffer passed in depends on both the a caller parameter and the
capabilities of the underlying SPI controller, meaning that a driver
can suddenly become buggy when used with a new co
On 18/11/2022 16:44, Mark Brown wrote:
The problem arrives when your controller does support 16-bits, so
your data is not swapped, but you still put the data on the bus
with 8-bit transfers.
Why would you need to use 8 bit transfers if the controller supports
16 bits?
No idea why this driv
On Fri, Nov 18, 2022 at 11:36:27AM +0100, Carlo Caione wrote:
> On 17/11/2022 15:59, Mark Brown wrote:
> > So this is an issue in the MIPI DBI code where the interpretation of the
> > buffer passed in depends on both the a caller parameter and the
> > capabilities of the underlying SPI controller,
The ILI9486 driver is wrongly assuming that the SPI panel is interfaced
only with 8-bit SPI controllers and consequently that the pixel data
passed by the MIPI DBI subsystem are already swapped before being sent
over SPI using 8 bits-per-word.
This is not always true for all the SPI controllers.
On 17/11/2022 12:09, Mark Brown wrote:
I don't understand what the commit log is saying here. The
meson-spicc driver advertises support for 8 bit words, if the driver
is sending data formatted as a byte stream everything should be fine.
It may be that there is some optimisation available from
On Thu, Nov 17, 2022 at 02:40:05PM +0100, Carlo Caione wrote:
> On 17/11/2022 12:09, Mark Brown wrote:
> > I don't understand what the commit log is saying here. The meson-spicc
> > driver advertises support for 8 bit words, if the driver is sending data
> > formatted as a byte stream everything
On Thu, Nov 17, 2022 at 09:47:40AM +0100, Carlo Caione wrote:
> The ILI9486 driver is wrongly assuming that the SPI panel is interfaced
> only with 8-bit SPI controllers and consequently that the pixel data
> passed by the MIPI DBI subsystem are already swapped before being sent
> over SPI using 8
