Re: [PATCH v2 2/3] scsi: ufs: Modulize ufs-bsg
From: Bjorn Andersson
Date: Thu Dec 12 2019 - 13:24:18 EST
On Thu 12 Dec 08:53 PST 2019, cang@xxxxxxxxxxxxxx wrote:
> On 2019-12-12 15:00, Avri Altman wrote:
> > > On Wed 11 Dec 22:01 PST 2019, cang@xxxxxxxxxxxxxx wrote:
> > > > On 2019-12-12 12:53, Bjorn Andersson wrote:
> > > > > On Wed 11 Dec 00:49 PST 2019, Can Guo wrote:
> > > > And in real cases, as the UFS is the boot device, UFS driver will always
> > > > be probed during bootup.
> > > >
> > >
> > > The UFS driver will load and probe because it's mentioned in the
> > > devicetree, but if either the ufs drivers or any of its dependencies
> > > (phy, resets, clocks, etc) are built as modules it might very well
> > > finish probing after lateinitcall.
> > >
> > > So in the even that the bsg is =y and any of these drivers are =m,
> > > or if
> > > you're having bad luck with your timing, the list will be empty.
> > >
> > > As described below, if bsg=m, then there's nothing that will load the
> > > module and the bsg will not probe...
> > Right.
> > bsg=y and ufshcd=m is a bad idea, and should be avoided.
> Yeah, I will get it addressed in the next patchset.
If you build this around platform_device_register_data() from ufshcd I
don't see a reason to add additional restrictions on this combination
(even though it might not make much sense for people to use this