From: Alan Stern <stern@rowland.harvard.edu>
To: Christoph Hellwig <hch@lst.de>,
Valentina Manea <valentina.manea.m@gmail.com>,
Shuah Khan <shuah@kernel.org>
Cc: Oliver Neukum <oneukum@suse.com>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>
Subject: Re: How to resolve an issue in swiotlb environment?
Date: Thu, 13 Jun 2019 13:16:32 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.4.44L0.1906131306580.1307-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <20190613073900.GC12093@lst.de>
On Thu, 13 Jun 2019, Christoph Hellwig wrote:
> On Wed, Jun 12, 2019 at 10:43:11AM -0400, Alan Stern wrote:
> > Would it be okay to rely on the assumption that USB block devices never
> > have block size < 512? (We could even add code to the driver to
> > enforce this, although refusing to handle such devices at all might be
> > worse than getting an occasional error.)
>
> sd.c only supports a few specific sector size, and none of them is
> < 512 bytes:
>
> if (sector_size != 512 &&
> sector_size != 1024 &&
> sector_size != 2048 &&
> sector_size != 4096) {
> ...
> sdkp->capacity = 0;
Great! So all we have to do is fix vhci-hcd. Then we can remove all
the virt_boundary_mask stuff from usb-storage and uas entirely.
(I'm assuming wireless USB isn't a genuine issue. As far as I know, it
is pretty much abandoned at this point.)
Valentina and Shua: Adding SG support to vhci-hcd shouldn't be too
hard. It ought to be possible even without changing the network
protocol.
Alan Stern
next prev parent reply other threads:[~2019-06-13 17:16 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-03 6:42 How to resolve an issue in swiotlb environment? Yoshihiro Shimoda
2019-06-07 12:00 ` Yoshihiro Shimoda
2019-06-10 7:31 ` Biju Das
2019-06-10 11:13 ` Yoshihiro Shimoda
2019-06-10 12:32 ` Christoph Hellwig
2019-06-10 18:46 ` Alan Stern
2019-06-11 6:41 ` Christoph Hellwig
2019-06-11 14:51 ` Alan Stern
2019-06-12 7:30 ` Christoph Hellwig
2019-06-12 8:52 ` Yoshihiro Shimoda
2019-06-12 11:31 ` Christoph Hellwig
2019-06-13 4:52 ` Yoshihiro Shimoda
2019-06-12 11:46 ` Oliver Neukum
2019-06-12 12:06 ` Christoph Hellwig
2019-06-12 14:43 ` Alan Stern
2019-06-13 7:39 ` Christoph Hellwig
2019-06-13 16:57 ` Martin K. Petersen
2019-06-13 17:16 ` Alan Stern [this message]
2019-06-13 18:18 ` Greg KH
2019-06-13 23:01 ` shuah
2019-06-14 14:44 ` Alan Stern
2019-06-18 15:28 ` shuah
2019-06-19 20:23 ` shuah
2019-06-19 21:05 ` Alan Stern
2019-06-21 17:43 ` Suwan Kim
2019-06-11 6:49 ` Yoshihiro Shimoda
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=Pine.LNX.4.44L0.1906131306580.1307-100000@iolanthe.rowland.org \
--to=stern@rowland.harvard.edu \
--cc=hch@lst.de \
--cc=iommu@lists.linux-foundation.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-renesas-soc@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=oneukum@suse.com \
--cc=shuah@kernel.org \
--cc=valentina.manea.m@gmail.com \
--cc=yoshihiro.shimoda.uh@renesas.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).