PROBLEM: pcie imx6 link problem after a random number of reboot

[Richard Zhu]

Hi Ivan:
Sorry to reply late.

> -----Original Message-----
> From: Ivan Grimaldi [mailto:grimaldi.ivan at gmail.com]
> Sent: Monday, July 18, 2016 6:45 PM
> To: Richard Zhu <hongxing.zhu at nxp.com>
> Cc: r65037 at freescale.com; l.stach at pengutronix.de; linux-pci at vger.kernel.org;
> bhelgaas at google.com; linux-arm-kernel at lists.infradead.org
> Subject: Re: PROBLEM: pcie imx6 link problem after a random number of
> reboot
> 
> Hi,
> 
>   i have enabled early printk and after a random number of restart the kernel
> hangs occurs later in the log (Below kernel log).
> 
> ...
> imx6q-pcie 1ffc000.pcie: Link up, Gen=2
> imx6q-pcie 1ffc000.pcie: PCI host bridge to bus 0000:00 pci_bus 0000:00: root
> bus resource [io  0x1000-0xffff] pci_bus 0000:00: root bus resource [mem
> 0x01000000-0x01efffff] pci_bus 0000:00: root bus resource [bus 00-ff] pci_bus
> 0000:00: scanning bus pci 0000:00:00.0: [16c3:abcd] type 01 class 0x060400 pci
> 0000:00:00.0: reg 0x10: [mem 0x00000000-0x000fffff] pci 0000:00:00.0: reg
> 0x38: [mem 0x00000000-0x0000ffff pref] pci 0000:00:00.0: calling
> pci_fixup_ide_bases+0x0/0x4c pci 0000:00:00.0: supports D1 pci 0000:00:00.0:
> PME# supported from D0 D1 D3hot D3cold pci 0000:00:00.0: PME# disabled
> pci_bus 0000:00: fixups for bus
> PCI: bus0: Fast back to back transfers disabled pci 0000:00:00.0: scanning [bus
> 01-01] behind bridge, pass 0 pci 0000:00:00.0: scanning [bus 00-00] behind
> bridge, pass 1 pci_bus 0000:01: scanning bus
> 
>
[Zhu hongxing] The pcie link is up refer to the log.
Is it hang here?

If yes, I suspect that the link is not stable, and the link is down here.
Can you use one pcie protocol analyzer to figure out what happen on the bus?

> 
> IVan
> 
> 
<snip...>

Best Regards
hongxing zhu
Linux BSP team
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Email: hongxing.zhu at nxp.com