Re: [PATCH v2 2/4] dfl: add dfl bus support to MODULE_DEVICE_TABLE()

[Moritz Fischer]

Hi Hao, Xu,

On Tue, Sep 15, 2020 at 05:58:46AM +0000, Wu, Hao wrote:
> > On Tue, Sep 15, 2020 at 12:08:38PM +0800, Wu, Hao wrote:
> > > > On Tue, Sep 15, 2020 at 11:27:51AM +0800, Xu Yilun wrote:
> > > > > Device Feature List (DFL) is a linked list of feature headers within the
> > > > > device MMIO space. It is used by FPGA to enumerate multiple sub
> > features
> > > > > within it. Each feature can be uniquely identified by DFL type and
> > > > > feature id, which can be read out from feature headers.
> > > > >
> > > > > A dfl bus helps DFL framework modularize DFL device drivers for
> > different
> > > > > sub features. The dfl bus matches its devices and drivers by DFL type
> > and
> > > > > feature id.
> > > > >
> > > > > This patch add dfl bus support to MODULE_DEVICE_TABLE() by adding
> > info
> > > > > about struct dfl_device_id in devicetable-offsets.c and add a dfl entry
> > > > > point in file2alias.c.
> > > > >
> > > > > Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
> > > > > Signed-off-by: Wu Hao <hao.wu@xxxxxxxxx>
> > > > > Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
> > > > > Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
> > > > > Acked-by: Wu Hao <hao.wu@xxxxxxxxx>
> > >
> > > Yilun,
> > >
> > > I haven't acked-by this patch as it doesn't modify any dfl files, ideally you
> > 
> > Sorry, I misunderstood your comments "Acked-by: xxx for DFL related
> > changes after this fix".

Yeah it wasn't entirely clear to me either :)
> 
> Because the first patch contains changes to non-dfl files as well. : )
> 
> Hao
> 
> > 
> > > need acked-by from real maintainer of scripts/mod code, right?
> > 
> > Ideally yes. From the MAINTAINERS it is Masahiro Yamada, I added him on
> > the "to"
> > list. But I see some other patches (also for devtable entries) in kernel
> > don't have his acked-by.

Yeah, I've looked at that and most patches for those files seem to be
from subsystem maintainers. So I *think* it should be fine?

> > 
> > Hi Moritz:
> > 
> > Do you have any ideas on that?
> > 
> > Thanks,
> > Yilun.
> > 
> > >
> > > Thanks
> > > Hao
> > >
> > > > > ---
> > > > > v2: add comments for the format of modalias
> > > > > ---
> > > > >  scripts/mod/devicetable-offsets.c |  4 ++++
> > > > >  scripts/mod/file2alias.c          | 17 +++++++++++++++++
> > > > >  2 files changed, 21 insertions(+)
> > > > >
> > > > > diff --git a/scripts/mod/devicetable-offsets.c
> > b/scripts/mod/devicetable-
> > > > offsets.c
> > > > > index 27007c1..d8350ee 100644
> > > > > --- a/scripts/mod/devicetable-offsets.c
> > > > > +++ b/scripts/mod/devicetable-offsets.c
> > > > > @@ -243,5 +243,9 @@ int main(void)
> > > > >  DEVID(mhi_device_id);
> > > > >  DEVID_FIELD(mhi_device_id, chan);
> > > > >
> > > > > +DEVID(dfl_device_id);
> > > > > +DEVID_FIELD(dfl_device_id, type);
> > > > > +DEVID_FIELD(dfl_device_id, feature_id);
> > > > > +
> > > > >  return 0;
> > > > >  }
> > > > > diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
> > > > > index 2417dd1..9fd2e60 100644
> > > > > --- a/scripts/mod/file2alias.c
> > > > > +++ b/scripts/mod/file2alias.c
> > > > > @@ -1368,6 +1368,22 @@ static int do_mhi_entry(const char
> > *filename,
> > > > void *symval, char *alias)
> > > > >  return 1;
> > > > >  }
> > > > >
> > > > > +/* Looks like: dfl:tNfN */
> > > > > +static int do_dfl_entry(const char *filename, void *symval, char *alias)
> > > > > +{
> > > > > +DEF_FIELD(symval, dfl_device_id, type);
> > > > > +DEF_FIELD(symval, dfl_device_id, feature_id);
> > > > > +
> > > > > +/*
> > > > > + * type contains 4 valid bits and feature_id contains 12 valid bits
> > > > > + * according to DFL specification.
> > > > > + */
> > > > > +sprintf(alias, "dfl:t%01Xf%03X", type, feature_id);
> > > > > +
> > > > > +add_wildcard(alias);
> > > > > +return 1;
> > > > > +}
> > > > > +
> > > > >  /* Does namelen bytes of name exactly match the symbol? */
> > > > >  static bool sym_is(const char *name, unsigned namelen, const char
> > > > *symbol)
> > > > >  {
> > > > > @@ -1442,6 +1458,7 @@ static const struct devtable devtable[] = {
> > > > >  {"tee", SIZE_tee_client_device_id, do_tee_entry},
> > > > >  {"wmi", SIZE_wmi_device_id, do_wmi_entry},
> > > > >  {"mhi", SIZE_mhi_device_id, do_mhi_entry},
> > > > > +{"dfl", SIZE_dfl_device_id, do_dfl_entry},
> > > > >  };
> > > > >
> > > > >  /* Create MODULE_ALIAS() statements.
> > > > > --
> > > > > 2.7.4
> > > > >
> > > > Applied to for-next,
> > > >
> > > > Thanks

Cheers,
Moritz