Re: [PATCH v7 2/4] mmc: sdhci-tegra: Add support to program MC stream ID

[Ulf Hansson]

On Thu, 13 Oct 2022 at 08:33, Prathamesh Shete <pshete@xxxxxxxxxx> wrote:
>
> Hi Ulf,
>
> >> In that case, perhaps we can add a "depends on IOMMU_API" in the Kconfig
> >> instead? Or is the tegra driver used on platforms where IOMMU_API could be
> >> unset?
> Yes it can/will work with IOMMU disabled so its not recommended to add a "depends on" condition in Kconfig.

Alright, in that case it looks to me that there are two other options
to move forward.

1) Add proper definitions of the struct iommu_fwspec in
include/linux/iommu.h even when CONFIG_IOMMU_API is unset. In a way it
seems a bit silly to me, to have the iommu stubs around, unless those
can be used for cases like this, right!?

2) Move the code within the "ifdef CONFIG_IOMMU_API" sections into
separate functions - and add stubs for these functions too. In this
way the functions can be called, independently of whether
CONFIG_IOMMU_API is set/unse, which would make the code in
drivers/mmc/host/sdhci-tegra.c cleaner and thus easier to maintain.


>
> Thanks
> Prathamesh
>
> > -----Original Message-----
> > From: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> > Sent: Tuesday, October 11, 2022 6:04 PM
> > To: Prathamesh Shete <pshete@xxxxxxxxxx>
> > Cc: adrian.hunter@xxxxxxxxx; thierry.reding@xxxxxxxxx; Jonathan Hunter
> > <jonathanh@xxxxxxxxxx>; p.zabel@xxxxxxxxxxxxxx; linux-
> > mmc@xxxxxxxxxxxxxxx; linux-tegra@xxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; Aniruddha Tvs Rao <anrao@xxxxxxxxxx>; Suresh
> > Mangipudi <smangipudi@xxxxxxxxxx>; Krishna Yarlagadda
> > <kyarlagadda@xxxxxxxxxx>
> > Subject: Re: [PATCH v7 2/4] mmc: sdhci-tegra: Add support to program MC
> > stream ID
> >
> > External email: Use caution opening links or attachments
> >
> >
> > On Tue, 11 Oct 2022 at 13:44, Prathamesh Shete <pshete@xxxxxxxxxx> wrote:
> > >
> > > Hi Ulf
> > >
> > > The initial patches were without the #ifdef. #ifdef is being added as per review
> > comments and kernel robot errors.
> > > Following error was detected by kernel robot
> > > >>
> > > All errors (new ones prefixed by >>):
> > >
> > >    drivers/mmc/host/sdhci-tegra.c: In function 'sdhci_tegra_probe':
> > > >> drivers/mmc/host/sdhci-tegra.c:1794:54: error: 'struct iommu_fwspec' has
> > no member named 'ids'
> > >     1794 |                         tegra_host->streamid = fwspec->ids[0] & 0xffff;
> > >          |                                                      ^~
> > >
> > >
> > > vim +1794 drivers/mmc/host/sdhci-tegra.c
> > > >>
> > > Adrian also pointed out this issue so to address these issues #ifdef
> > > was added
> >
> > I see!
> >
> > In that case, perhaps we can add a "depends on IOMMU_API" in the Kconfig
> > instead? Or is the tegra driver used on platforms where IOMMU_API could be
> > unset?
> >
> > [...]

Kind regards
Uffe