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

[Konrad Dybcio]

On 6/30/26 11:52 AM, Mukesh Savaliya wrote:
> 
> 
> On 6/29/2026 1:33 PM, Pengyu Luo wrote:
>> 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.
>>
> If firmware doesn't program in GSI, you can't have this working in GSI mode, its going to fail (and work with fallback). if it's programmed in GSI, anyway this will run in GSI mode. So why to add extra things without any usage ?

My understanding is that GSI mode works, but the the FIFO_DISABLE bit
is set to zero, so FIFO mode is chosen.

So NHLOS would allow the use of this GPI instance (and not reserve the
GPI channels for this SE), but not set FIFO_DISABLE=1.

Konrad