Re: [PATCH v7 0/5] Reset PCIe devices to address DMA problem on kdumpwith iommu

From: Takao Indoh
Date: Wed Jan 23 2013 - 19:23:35 EST


(2013/01/23 9:47), Thomas Renninger wrote:
On Monday, January 21, 2013 10:11:04 AM Takao Indoh wrote:
(2013/01/08 4:09), Thomas Renninger wrote:
...
I tried the provided patches first on 2.6.32, then I verfied with 3.8-rc2
and in both cases the disk is not detected anymore in
reset_devices (kexec'ed/kdump) case (but things work fine without these
patches).

So the problem that the disk is not detected was caused by exactmap
problem you guys are discussing? Or still not detected even if exactmap
problem is fixed?
This problem is related to the 5 PCI resetting patches.
Dumping worked with a 2.6.32 and a 3.8-rc2 kernel, adding the PCI resetting
patches broke both. I first tried 2.6.32 and verified with 3.8-rc2 to make sure
I didn't mess up the backport adjustings of the patches to 2.6.32.

If you have a chance please try again the patches with the latest
firmware. I met another problem on megaraid_sas disk when I tested the
patches and it did not occur after updated its firmware to the latest
one.
Unfortunately this Dell platform takes really long to boot.
I can give it the one or other test, but please do not bomb me with patches.

For info:
About the interrupt remapping error interrupt storm in kdump case I tried to
reproduce on this machine, but never could: The guys who saw that also cannot
reproduce this anymore.

Two ideas I had about this:
- As said already, (also) try to catch the error case and try to reset the
the device in AER/Specific iterrupt remapping error interrupt caught.
- Have a look at coreboot, these guys should know how to initialize the PCI
subsystem from scratch and might have some well tested PCI resetting
code in place already (no idea, just a thought).

Ok, at first I'll take a look at AER code to check how it resets devices
on PCIe error.

Thanks,
Takao Indoh


Thomas



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/