Re: [PATCH 2/2] spi: qcom-geni: Add property to force GSI mode

[Pengyu Luo]

On Mon, Jun 29, 2026 at 1:36 PM Mukesh Savaliya
<mukesh.savaliya@xxxxxxxxxxxxxxxx> wrote:
>
> Hi Pengyu,
>
> On 6/15/2026 2:48 AM, Dmitry Baryshkov wrote:
> > On Sun, Jun 14, 2026 at 04:34:24PM +0800, Pengyu Luo wrote:
> >> Some devices (such as gaokun3) do not disable FIFO mode, causing the
> >> driver to fallback to FIFO mode by default. However, these platforms
> >> also support GSI mode, which is highly preferred for certain
> >> peripherals like SPI touchscreens to improve performance.
> >>
> >> Introduce the "qcom,force-gsi-mode" device property to hint and force
> >> the controller into GSI mode during initialization.
> Why to force ? You can directly configure in GSI mode. Note there are
> some configuration done prior to Linux bootup too.

Sorry, I don't get it. how? I know there may be a qupfw, but it is
impossible for a normal user like me to generate one with GSI
preferred.

Best wishes,
Pengyu

> >
> > Ideally, this should be decided by the SPI controller based on the
> > requirements. Another option would be to prefer GSI for all transfers if
> > it is available, ignoring the FIFO even if it is not disabled.
> >
> Yes, it should be decided in advance and configured accordingly for GSI
> vs non GSI mode. Because there would be limited set of GSI pipes, which
> will actually make must have GSI mode device run with FIFO mode.
>
> Why don't you decide prior and configure for GSI mode ? We don't need to
> change the current logic of deciding FIFO vs GSI.
> >>
> >> Signed-off-by: Pengyu Luo <mitltlatltl@xxxxxxxxx>
> >> ---
> >>   drivers/spi/spi-geni-qcom.c | 7 +++++++
> >>   1 file changed, 7 insertions(+)
> >>
> >
>