All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
To: Will Deacon <will@kernel.org>
Cc: iommu@lists.linux-foundation.org, robin.murphy@arm.com,
	sspatil@android.com
Subject: Re: Users of IOMMU_QCOM_SYS_CACHE?
Date: Thu, 24 Oct 2019 17:01:05 +0530	[thread overview]
Message-ID: <257ea3fb1740ba7b968e1ddfbbb94a52@codeaurora.org> (raw)
In-Reply-To: <20191024112130.GD1242@willie-the-truck>

On 2019-10-24 16:51, Will Deacon wrote:
> On Thu, Oct 24, 2019 at 04:41:04PM +0530, Sai Prakash Ranjan wrote:
>> On 2019-10-24 16:21, Will Deacon wrote:
>> > In commit 90ec7a76cc4b ("iommu/io-pgtable-arm: Add support to use system
>> > cache") we added support for IOMMU_QCOM_SYS_CACHE which was merged into
>> > 5.3.
>> > This allows non-coherent devices to request an outer cacheable memory
>> > type.... except that nobody actually does this in mainline. I remember
>> > there
>> > being a potential DRM user but I don't know what happened to it.
>> >
>> > Given that this isn't actually exposed in the DMA API, I worry that
>> > we're
>> > just carrying part of an out-of-tree hack here and propose that we drop
>> > the flag altogether unless we get an upstream user, preferably by
>> > plumbing
>> > this into the DMA API via a new attribute.
>> >
>> > Thoughts?
>> >
>> 
>> There is definitely a user of this coming soon atleast for SC7180 SoC 
>> once
>> we have support for this SoC upstream.
> 
> Ok, I'm keen to see how you end up using this. How soon is soon?
> 

We have already started upstreaming for SC7180, so this should also come 
pretty soon. Sorry, I cannot tell the exact date but can make sure that 
your message reaches to appropriate team.

Thanks,
Sai

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a 
member
of Code Aurora Forum, hosted by The Linux Foundation
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  reply	other threads:[~2019-10-24 11:31 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-24 10:51 Users of IOMMU_QCOM_SYS_CACHE? Will Deacon
2019-10-24 11:11 ` Sai Prakash Ranjan
2019-10-24 11:21   ` Will Deacon
2019-10-24 11:31     ` Sai Prakash Ranjan [this message]
2019-10-24 15:38 ` Jordan Crouse

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=257ea3fb1740ba7b968e1ddfbbb94a52@codeaurora.org \
    --to=saiprakash.ranjan@codeaurora.org \
    --cc=iommu@lists.linux-foundation.org \
    --cc=robin.murphy@arm.com \
    --cc=sspatil@android.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.