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Message-ID: <4ffc662d-5c73-5047-81d5-ad78ca3a7d7e@huawei.com>
Date:   Thu, 13 Oct 2022 08:07:46 +0100
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Subject: Re: [PATCH AUTOSEL 5.15 10/47] iommu/arm-smmu-v3: Make default domain
 type of HiSilicon PTT device to identity
To:     Sasha Levin <sashal@kernel.org>, <linux-kernel@vger.kernel.org>,
        <stable@vger.kernel.org>
CC:     Yicong Yang <yangyicong@hisilicon.com>,
        Will Deacon <will@kernel.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        <joro@8bytes.org>, <robin.murphy@arm.com>,
        <baolu.lu@linux.intel.com>, <jgg@ziepe.ca>, <tglx@linutronix.de>,
        <shameerali.kolothum.thodi@huawei.com>,
        <christophe.jaillet@wanadoo.fr>,
        <linux-arm-kernel@lists.infradead.org>, <iommu@lists.linux.dev>
References: <20221013002124.1894077-1-sashal@kernel.org>
 <20221013002124.1894077-10-sashal@kernel.org>
From:   John Garry <john.garry@huawei.com>
In-Reply-To: <20221013002124.1894077-10-sashal@kernel.org>
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On 13/10/2022 01:20, Sasha Levin wrote:
> From: Yicong Yang<yangyicong@hisilicon.com>
> 
> [ Upstream commit 24b6c7798a0122012ca848ea0d25e973334266b0 ]
> 
> The DMA operations of HiSilicon PTT device can only work properly with
> identical mappings. So add a quirk for the device to force the domain
> as passthrough.
> 
> Acked-by: Will Deacon<will@kernel.org>
> Signed-off-by: Yicong Yang<yangyicong@hisilicon.com>
> Reviewed-by: John Garry<john.garry@huawei.com>
> Link:https://lore.kernel.org/r/20220816114414.4092-2-yangyicong@huawei.com
> Signed-off-by: Mathieu Poirier<mathieu.poirier@linaro.org>
> Signed-off-by: Sasha Levin<sashal@kernel.org>
> ---
>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)

I don't think that this commit should be backported to any stable tree. 
It's only required for a new driver.

Thanks,
John