Hi Greg,
> -----Original Message-----
> From: Greg KH <gre...@linuxfoundation.org>
> Sent: Sunday, January 24, 2021 5:27 PM
> To: Thokala, Srikanth <srikanth.thok...@intel.com>
> Cc: mgr...@linux.intel.com; markgr...@kernel.org; a...@arndb.de;
> b...@suse.de; damien.lem...@wdc.com; dragan.cve...@xilinx.com;
> cor...@lwn.net; leonard.cres...@nxp.com; palmerdabb...@google.com;
> paul.walms...@sifive.com; peng....@nxp.com; robh...@kernel.org;
> shawn...@kernel.org; jassisinghb...@gmail.com; linux-
> ker...@vger.kernel.org; Derek Kiernan <derek.kier...@xilinx.com>
> Subject: Re: [PATCH v2 09/34] misc: xlink-pcie: lh: Add PCIe EPF driver
> for Local Host
>
> On Sun, Jan 24, 2021 at 11:48:29AM +0000, Thokala, Srikanth wrote:
> > > > +{
> > > > + struct pci_epf_bar *epf_bar;
> > > > + bool bar_fixed_64bit;
> > > > + int ret, i;
> > > > +
> > > > + for (i = BAR_0; i <= BAR_5; i++) {
> > > > + epf_bar = &epf->bar[i];
> > > > + bar_fixed_64bit = !!(epc_features->bar_fixed_64bit & (1
> <<
> > > i));
> > > > + if (bar_fixed_64bit)
> > > > + epf_bar->flags |= PCI_BASE_ADDRESS_MEM_TYPE_64;
> > > > + if (epc_features->bar_fixed_size[i])
> > > > + epf_bar->size = epc_features->bar_fixed_size[i];
> > > > +
> > > > + if (i == BAR_2) {
> > > > + ret = intel_xpcie_check_bar(epf, epf_bar, BAR_2,
> > > > + BAR2_MIN_SIZE,
> > > > +
> > > > epc_features->reserved_bar);
> > > > + if (ret)
> > > > + return ret;
> > > > + }
> > > > +
> > > > + if (i == BAR_4) {
> > > > + ret = intel_xpcie_check_bar(epf, epf_bar, BAR_4,
> > > > + BAR4_MIN_SIZE,
> > > > +
> > > > epc_features->reserved_bar);
> > > > + if (ret)
> > > > + return ret;
> > > > + }
> > >
> > > Why do you need to check all of this? Where is the data coming from
> > > that could be incorrect?
> >
> > PCI BAR attributes, as inputs, are coming from the PCIe controller
> driver
> > through PCIe End Point Framework. These checks are required to compare
> the
> > configuration this driver is expecting to the configuration coming from
> > the PCIe controller driver.
>
> So why do you not trust that information coming from the caller?
> Shouldn't it always be correct as it already is validated by that
> in-kernel caller? Don't check for things you don't have to check for
> because you control the code that calls this stuff.
Sure, I agree to your point.
I will fix it in my next version.
Thanks!
Srikanth
>
> thanks,
>
> greg k-h
