From: Christoph Hellwig <hch@lst.de>
To: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Christoph Hellwig <hch@lst.de>,
Alan Stern <stern@rowland.harvard.edu>,
Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>
Subject: Re: How to resolve an issue in swiotlb environment?
Date: Mon, 10 Jun 2019 14:32:22 +0200 [thread overview]
Message-ID: <20190610123222.GA20985@lst.de> (raw)
In-Reply-To: <OSAPR01MB3089BCA7CF78D6E4D9C83E1BD8130@OSAPR01MB3089.jpnprd01.prod.outlook.com>
Hi Yoshihiro,
sorry for not taking care of this earlier, today is a public holiday
here and thus I'm not working much over the long weekend.
On Mon, Jun 10, 2019 at 11:13:07AM +0000, Yoshihiro Shimoda wrote:
> I have another way to avoid the issue. But it doesn't seem that a good way though...
> According to the commit that adding blk_queue_virt_boundary() [3],
> this is needed for vhci_hcd as a workaround so that if we avoid to call it
> on xhci-hcd driver, the issue disappeared. What do you think?
> JFYI, I pasted a tentative patch in the end of email [4].
Oh, I hadn't even look at why USB uses blk_queue_virt_boundary, and it
seems like the usage is wrong, as it doesn't follow the same rules as
all the others. I think your patch goes in the right direction,
but instead of comparing a hcd name it needs to be keyed of a flag
set by the driver (I suspect there is one indicating native SG support,
but I can't quickly find it), and we need an alternative solution
for drivers that don't see like vhci. I suspect just limiting the
entire transfer size to something that works for a single packet
for them would be fine.
next prev parent reply other threads:[~2019-06-10 12:32 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <OSAPR01MB3089B381AF2F687526E63EEAD8140@OSAPR01MB3089.jpnprd01.prod.outlook.com>
[not found] ` <OSAPR01MB3089D50DBDAA6C7D427E72EED8100@OSAPR01MB3089.jpnprd01.prod.outlook.com>
2019-06-10 7:31 ` How to resolve an issue in swiotlb environment? Biju Das
2019-06-10 11:13 ` Yoshihiro Shimoda
2019-06-10 12:32 ` Christoph Hellwig [this message]
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
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=20190610123222.GA20985@lst.de \
--to=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=stern@rowland.harvard.edu \
--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).