Re: 4.3 kernel panics when MMC/SDHC card is inserted on thinkpad

From: Joerg Roedel
Date: Mon Dec 05 2016 - 05:23:49 EST


Hi David,

On Sun, Dec 04, 2016 at 06:57:57PM -0600, David F wrote:
> Aug 19 13:32:20 taz [ 156.425627] ------------[ cut here ]------------
> Aug 19 13:32:20 taz [ 156.428136] kernel BUG at
> drivers/iommu/intel-iommu.c:3682!

This BUG_ON triggered because the IOMMU driver can't find a domain for
the device passed to intel_unmap. This looks like an IOMMU bug, but I am
not 100% sure yet, because if there is no domain for a device the
intel_map_page path returns 0 and the intel_unmap function should not be
called.

I need a couple of things to track this down. Can you please build a
kernel with CONFIG_DMA_API_DEBUG=y and boot the kernel with IOMMU
disabled? Insert and remove an SD-Card with this kernel and send me a
full dmesg.

Please also send me the output of 'lspci -v' and a full dmesg with IOMMU
enabled and the BUG triggered.


Thanks,

Joerg