Re: [PATCH v2 1/8] PCI: rcar-gen2: Add support for clocks

[Herve Codina <herve.codina@bootlin.com>]

Hi Geert,

On Thu, 14 Apr 2022 10:45:54 +0200
Geert Uytterhoeven <geert@linux-m68k.org> wrote:

> Hi Hervé,
> 
> Thanks for your patch!
> 
> On Thu, Apr 14, 2022 at 9:40 AM Herve Codina <herve.codina@bootlin.com> wrote:
> > The PCI rcar-gen2 does not call any clk_prepare_enable().  
> 
> Correct, this driver manages the clocks indirectly through Runtime PM.
> 
> > This lead to an access failure when the driver tries to access
> > the IP (at least on a RZ/N1D platform).  
> 
> I expect adding
> 
>     power-domans = <&sysctrl>;
> 
> to the pci_usb node makes this patch redundant.

Seems not enough.
I tried what you suggest :
 - Added 'power-domains = <&systrl>;' to the pci_usb node
 - Added missing '#power-domain-cells = <0>;' to sysctrl node
 - Reverted my patch.

The system crashed at boot:
--- 8< ---
...
[    0.705309] loop: module loaded
[    0.709597] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[    0.716804] ehci-pci: EHCI PCI platform driver
[    0.721716] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[    0.728522] ohci-pci: OHCI PCI platform driver
[    0.733581] usbcore: registered new interface driver usb-storage
[    0.740458] ThumbEE CPU extension supported.
[    0.745093] Registering SWP/SWPB emulation handler
[    0.797518] rzn1-pinctrl 40067000.pinctrl: probed
[    0.803311] pci-rcar-gen2 40030000.pci: host bridge /soc/pci@40030000 ranges:
[    0.811255] pci-rcar-gen2 40030000.pci:      MEM 0x0040020000..0x004002ffff -> 0x0040020000
[    0.820373] pci-rcar-gen2 40030000.pci:   IB MEM 0x0080000000..0x00bfffffff -> 0x0080000000
[    0.829609] 8<--- cut here ---
[    0.832958] Unhandled fault: external abort on non-linefetch (0x1008) at 0x90b5f848
[    0.841259] [90b5f848] *pgd=82149811, *pte=40030653, *ppte=40030453
[    0.848093] Internal error: : 1008 [#1] SMP ARM
[    0.853024] Modules linked in:
[    0.856398] CPU: 0 PID: 31 Comm: kworker/u4:1 Not tainted 5.18.0-rc2-00009-g803ee9fd9fa5-dirty #5
[    0.865998] Hardware name: Generic DT based system
[    0.871176] Workqueue: events_unbound deferred_probe_work_func
[    0.877539] PC is at rcar_pci_probe+0x15c/0x2f8
[    0.882454] LR is at _raw_spin_unlock_irqrestore+0x24/0x2c
[    0.888434] pc : [<803ea428>]    lr : [<804dc9b0>]    psr: 60000013
[    0.895193] sp : 90aa5e40  ip : 8217c4e0  fp : 00000000
[    0.900857] r10: 80e7bd30  r9 : 80000000  r8 : 40000000
[    0.906532] r7 : 80000000  r6 : 8217c410  r5 : 821d3400  r4 : 90b5f000
[    0.913580] r3 : 00000009  r2 : 5c120fb6  r1 : 60000013  r0 : 00000000
[    0.920646] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[    0.928365] Control: 10c5387d  Table: 8000406a  DAC: 00000051
...
--- 8< ---

I also added a trace printk in r9a06g032-clocks.c and
r9a06g032_attach_dev() was never called.

Did I miss to set something ?

Regards,
Hervé