From: Robin Murphy <robin.murphy@arm.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>,
iommu@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] dma-mapping: don't return errors from dma_set_seg_boundary
Date: Fri, 2 Aug 2024 12:53:01 +0100 [thread overview]
Message-ID: <a1a07edf-9ab2-4121-a230-0d06bda3bf3d@arm.com> (raw)
In-Reply-To: <20240801133353.GA1846@lst.de>
On 01/08/2024 2:33 pm, Christoph Hellwig wrote:
> On Thu, Aug 01, 2024 at 01:36:01PM +0100, Robin Murphy wrote:
>> I guess I assumed that the old block layer bodges in this area had been
>> cleaned up already - perhaps it *is* high time for whatever's left to grow
>> a proper understanding of whether a block device actually does its own DMA
>> or not.
>
> Can you point to a discussion on that? The concepts here don't make
> quite sense to me.
No specific discussion, I just have a vague memory of hacks in the USB
layer when I first started looking at this stuff 10 years ago... From a
bit of digging to try to remind myself, I'm fairly sure that must have
been the block bounce related stuff, which you cleaned up in
6eb0233ec2d0 ("usb: don't inherity DMA properties for USB devices") a
while back.
Cheers,
Robin.
next prev parent reply other threads:[~2024-08-02 11:53 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-23 0:05 remove the dma_set_{max_seg_size,seg_boundary,min_align_mask} return value Christoph Hellwig
2024-07-23 0:05 ` [PATCH 1/3] dma-mapping: don't return errors from dma_set_min_align_mask Christoph Hellwig
2024-07-23 0:05 ` [PATCH 2/3] dma-mapping: don't return errors from dma_set_seg_boundary Christoph Hellwig
2024-08-01 12:00 ` Marek Szyprowski
2024-08-01 12:36 ` Robin Murphy
2024-08-01 13:33 ` Christoph Hellwig
2024-08-02 11:53 ` Robin Murphy [this message]
2024-07-23 0:05 ` [PATCH 3/3] dma-mapping: don't return errors from dma_set_max_seg_size Christoph Hellwig
2024-07-30 13:13 ` remove the dma_set_{max_seg_size,seg_boundary,min_align_mask} return value Robin Murphy
2024-07-30 15:20 ` Christoph Hellwig
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