Re: [PATCH 1/2] ufs: core: Add quriks for VCC ramp-up delay
From: Ed Tsai (蔡宗軒)
Date: Thu Mar 05 2026 - 19:19:48 EST
On Thu, 2026-03-05 at 06:24 -0600, Bart Van Assche wrote:
> On 3/5/26 2:29 AM, ed.tsai@xxxxxxxxxxxx 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)?
>
> Thanks,
>
> Bart.
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?
Best,
Ed Tsai