From: Christoph Hellwig <hch@lst.de>
To: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Carol L Soto <clsoto@us.ibm.com>,
iommu@lists.linux-foundation.org, linuxppc-dev@lists.ozlabs.org,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH kernel] powerpc/iommu: Report the correct most efficient DMA mask for PCI devices
Date: Thu, 30 Sep 2021 07:43:28 +0200 [thread overview]
Message-ID: <20210930054328.GA22181@lst.de> (raw)
In-Reply-To: <20210930034454.95794-1-aik@ozlabs.ru>
On Thu, Sep 30, 2021 at 01:44:54PM +1000, Alexey Kardashevskiy wrote:
> and returns the IOMMU table mask on the pseries platform which makes some
> drivers (mpt3sas is one example) choose 32bit DMA even though bypass is
> supported. The powernv platform sort of handles it by having a bigger
> default window with a mask >=40 but it only works as drivers choose
> 63/64bit if the required mask is >32 which is rather pointless.
>
> This reintroduces the bypass capability check to let drivers make
> a better choice of the DMA mask.
>
> Fixes: f1565c24b596 ("powerpc: use the generic dma_ops_bypass mode")
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
next prev parent reply other threads:[~2021-09-30 5:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-30 3:44 [PATCH kernel] powerpc/iommu: Report the correct most efficient DMA mask for PCI devices Alexey Kardashevskiy
2021-09-30 5:43 ` Christoph Hellwig [this message]
2021-10-01 14:36 ` Michael Ellerman
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