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Date: Mon, 1 Dec 2025 09:42:44 -0800
From: Jacob Pan <jacob.pan@linux.microsoft.com>
To: Will Deacon <will@kernel.org>
Cc: linux-kernel@vger.kernel.org, "iommu@lists.linux.dev"
 <iommu@lists.linux.dev>, Joerg Roedel <joro@8bytes.org>, Mostafa Saleh
 <smostafa@google.com>, Jason Gunthorpe <jgg@nvidia.com>, Robin Murphy
 <robin.murphy@arm.com>, Nicolin Chen <nicolinc@nvidia.com>, Zhang Yu
 <zhangyu1@linux.microsoft.com>, Jean Philippe-Brucker
 <jean-philippe@linaro.org>, Alexander Grest <Alexander.Grest@microsoft.com>
Subject: Re: [PATCH v4 1/2] iommu/arm-smmu-v3: Fix CMDQ timeout warning
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Hi Will,

On Tue, 25 Nov 2025 17:19:16 +0000
Will Deacon <will@kernel.org> wrote:

> I'm assuming you're seeing problems with an emulated command queue?
> Any chance you could make that bigger?
Yes, it was initially observed on HyperV emulated CMDQ with small queue
size, which was chosen for latency reasons.

But as I explained in the other thread, the queue space polling timeout
detection problem is not directly related to queue size. It is a
code logic bug IMHO.

Sorry I forgot to directly answer these.