Re: pci-usb/pci-sata broken with LPAE config after "reduce use of block bounce buffers"

From: Kishon Vijay Abraham I <kishon@ti.com>
To: Christoph Hellwig <hch@lst.de>
Cc: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>
Subject: Re: pci-usb/pci-sata broken with LPAE config after "reduce use of block bounce buffers"
Date: Wed, 5 Feb 2020 14:02:51 +0530	[thread overview]
Message-ID: <4a8bf1d3-6f8e-d13e-eae0-4db54f5cab8c@ti.com> (raw)
In-Reply-To: <20200205074719.GA22701@lst.de>

Christoph,

On 05/02/20 1:17 PM, Christoph Hellwig wrote:
> On Wed, Feb 05, 2020 at 10:45:24AM +0530, Kishon Vijay Abraham I wrote:
>>> Ok, this mostly like means we allocate a swiotlb buffer that isn't
>>> actually addressable.  To verify that can you post the output with the
>>> first attached patch?  If it shows the overflow message added there,
>>> please try if the second patch fixes it.
>>
>> I'm seeing some sort of busy loop after applying your 1st patch. I sent
>> a SysRq to see where it is stuck
> 
> And that shows up just with the patch?  Really strange as it doesn't
> change any blockig points.  What also is strange is that I don't see
> any of the warnings that should be there.  FYI, the slightly updated
> version of the patch that went through my testing it here:
> 
>     git://git.infradead.org/users/hch/misc.git swiotlb-debug
> 
> Gitweb:
> 
>     http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/swiotlb-debug
> 
> this also includes what was the second patch in the previous mail.  Can
> you try that branch?

I see data mismatch with that branch.

Kernel log: https://pastebin.ubuntu.com/p/9g9cm7GzRh/
Kernel Config: https://pastebin.ubuntu.com/p/gYfpRDdVry/
Repo: https://github.com/kishon/linux-wip.git swiotlb-debug (Added an
additional patch for fixing a interrupt issue over your branch).

Thanks
Kishon