Re: [PATCH V4 0/6] Enhancements to Tegra194 PCIe driver

[Vidya Sagar]

> -----Original Message-----
> From: Thierry Reding <thierry.reding@xxxxxxxxx>
> Sent: Wednesday, November 25, 2020 11:27 PM
> To: Vidya Sagar <vidyas@xxxxxxxxxx>
> Cc: lorenzo.pieralisi@xxxxxxx; robh+dt@xxxxxxxxxx; bhelgaas@xxxxxxxxxx;
> Jonathan Hunter <jonathanh@xxxxxxxxxx>; amanharitsh123@xxxxxxxxx;
> dinghao.liu@xxxxxxxxxx; kw@xxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; linux-
> tegra@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Krishna Thota
> <kthota@xxxxxxxxxx>; Manikanta Maddireddy <mmaddireddy@xxxxxxxxxx>;
> sagar.tv@xxxxxxxxx
> Subject: Re: [PATCH V4 0/6] Enhancements to Tegra194 PCIe driver
>
> On Mon, Nov 09, 2020 at 10:49:31PM +0530, Vidya Sagar wrote:
> > This series of patches do some enhancements and some bug fixes to the
> > Tegra194 PCIe platform driver like
> > - Fix Vendor-ID corruption
> > - Map DBI space correctly
> > - Update DWC IP version
> > - Continue with uninitialization sequence even if parts fail
> > - Check return value of tegra_pcie_init_controller()
> >
> > V4:
> > * Added a new patch to address link-up issues with some of the cards
> >
> > V3:
> > * Addressed Bjorn's review comments
> > * Split earlier patch-4 into two
> >   - Continue with the uninitialization sequence even if some parts fail
> >   - Check return value of tegra_pcie_init_controller() and exit
> > accordingly
> >
> > V2:
> > * Addressed Rob's comments. Changed 'Strongly Ordered' to 'nGnRnE'
> >
> > Vidya Sagar (6):
> >   PCI: tegra: Fix ASPM-L1SS advertisement disable code
> >   PCI: tegra: Map configuration space as nGnRnE
> >   PCI: tegra: Set DesignWare IP version
> >   PCI: tegra: Continue unconfig sequence even if parts fail
> >   PCI: tegra: Check return value of tegra_pcie_init_controller()
> >   PCI: tegra: Disable LTSSM during L2 entry
> >
> >  drivers/pci/controller/dwc/pcie-tegra194.c | 78
> > +++++++++++-----------
> >  1 file changed, 39 insertions(+), 39 deletions(-)
>
> I was going to test this series, but then I noticed that PCI is causing a crash on
> linux-next (as of fairly recently).
I root caused the crash issue to the following commit
a0fd361db8e5 ("PCI: dwc: Move "dbi", "dbi2", and "addr_space" resource 
setup into common code")

I also pushed the following two patches to fix this issue for review

http://patchwork.ozlabs.org/project/linux-pci/patch/20201125192234.2270-1-vidyas@xxxxxxxxxx/
http://patchwork.ozlabs.org/project/linux-pci/patch/20201125192554.5401-1-vidyas@xxxxxxxxxx/


> So I tried applying this on top of v5.10-rc1, but
> that gives me the following:
>
> 	[    3.595161] ahci 0001:01:00.0: version 3.0
> 	[    3.595726] ahci 0001:01:00.0: SSS flag set, parallel bus scan disabled
> 	[    4.609923] ahci 0001:01:00.0: controller reset failed (0xffffffff)
> 	[    4.610343] ahci: probe of 0001:01:00.0 failed with error -5
>
> So the device enumerates fine, but it's not able to reset the SATA controller.
> That said, this seems to happen regardless of this patch series, so plain v5.10-rc1
> also shows the above.
This was also a known issue and we need the following commit to make 
things work (FWIW, it is already accepted)
9fff3256f93d PCI: dwc: Restore ATU memory resource setup to use last entry

Otherwise, v5.10-rc3 can be used which has working state of PCIe on 
Tegra194.

> Given the above, I think we should hold off on applying this series until we've
> fixed PCI on linux-next and made sure that SATA also works properly, otherwise
> we don't have a known good baseline to test this against.
>
> Thierry