Re: [PATCH 1/2] ufs: core: Add quriks for VCC ramp-up delay

[Bart Van Assche <bvanassche@acm.org>]

On 3/5/26 6:19 PM, Ed Tsai (蔡宗軒) wrote:
> On Thu, 2026-03-05 at 06:24 -0600, Bart Van Assche wrote:
>> On 3/5/26 2:29 AM, ed.tsai@mediatek.com wrote:
>>> +     /*
>>> +      * On platforms with a slow VCC ramp-up, a delay is needed
>>> after
>>> +      * turning on VCC to ensure the voltage is stable before the
>>> +      * reference clock is enabled.
>>> +      */
>>> +     if (hba->quirks & UFSHCD_QUIRK_VCC_ON_DELAY && !ret && vcc_on
>>> &&
>>> +         hba->vreg_info.vcc && !hba->vreg_info.vcc->always_on)
>>> +             usleep_range(1000, 1100);
>>
>> Since the value of the delay is platform-dependent, has it been
>> considered to introduce a new vendor operation (vop)?
>
> A vop does feel a bit heavyweight for a simple sleep. How about we add
> a new configurable variable, similar to the approach used for the VCC
> off delay?

Let's postpone introducing such a configuration variable until there is
a real need for such a configuration variable.

Bart.