Re: [PATCH] Revert "phy: qualcomm: usb28nm: Add MDM9607 init sequence"

From: Vinod Koul
Date: Tue Jan 17 2023 - 00:36:27 EST


On 16-01-23, 21:35, Marijn Suijten wrote:
> On 2023-01-13 23:16:15, Vinod Koul wrote:
> > On 14-12-22, 23:37, Marijn Suijten wrote:
> > > This reverts commit 557a28811c7e0286d3816842032db5eb7bb5f156.
> > >
> > > This commit introduced an init sequence from downstream DT [1] in the
> > > driver. As mentioned by the comment above the HSPHY_INIT_CFG macro for
> > > this sequence:
> > >
> > > /*
> > > * The macro is used to define an initialization sequence. Each tuple
> > > * is meant to program 'value' into phy register at 'offset' with 'delay'
> > > * in us followed.
> > > */
> > >
> > > Instead of corresponding to offsets into the phy register, the sequence
> > > read by the downstream driver [2] is passed into ulpi_write [3] which
> > > crafts the address-value pair into a new value and writes it into the
> > > same register at USB_ULPI_VIEWPORT [4]. In other words, this init
> > > sequence is programmed into the hardware in a totally different way than
> > > downstream and is unlikely to achieve the desired result, if the hsphy
> > > is working at all.
> > >
> > > An alternative method needs to be found to write these init values at
> > > the desired location. Fortunately mdm9607 did not land upstream yet [5]
> > > and should have its compatible revised to use the generic one, instead
> > > of a compatible that writes wrong data to the wrong registers.
> >
> > Applied after adding missing subsystem tag, thanks
>
> Thanks, it wasn't clear to me whether to suffix the title when already
> included in the Revert: "phy: qualcomm: ..." title :)

A revert patch is a patch as well so the patch rules apply there as well,
so should say "subsystem tag: other tags: Revert foo..."

Thanks
--
~Vinod