From: Christoph Hellwig <hch@lst.de>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Tom Yan <tom.ty89@gmail.com>, Hans de Goede <hdegoede@redhat.com>,
Christoph Hellwig <hch@lst.de>,
linux-usb <linux-usb@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
SCSI development list <linux-scsi@vger.kernel.org>
Subject: Re: [PATCH 2/2] usb-storage: revert from scsi_add_host_with_dma() to scsi_add_host()
Date: Fri, 26 Feb 2021 06:53:52 +0100 [thread overview]
Message-ID: <20210226055352.GA2996@lst.de> (raw)
In-Reply-To: <20210225163557.GC1350993@rowland.harvard.edu>
On Thu, Feb 25, 2021 at 11:35:57AM -0500, Alan Stern wrote:
> This thread seems to have fallen through the cracks. Maybe now would be
> a good time to address the problem (since we originally planned to fix
> it in 5.11!).
>
> The questions listed below are pretty self-contained, although the rest
> of the discussion isn't. But I never received any answers.
usb-storage must use scsi_add_host_with_dma to use the right device
for DMA mapping and parameters. The calls to set the DMA options
on the device are needed so that IOMMU merging doesn't change the
imposed requirements. If these requirements slow you down you need
to relax them, as apparently the hardware is able to handle bigger
limits.
next prev parent reply other threads:[~2021-02-26 5:54 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20201128154849.3193-2-tom.ty89@gmail.com>
[not found] ` <5e62c383-22ea-6df6-5acc-5e9f381d4632@redhat.com>
[not found] ` <CAGnHSEnetAJNqUEW-iuq7eVyU6VnP84cv9+OVL4C5Z2ZK_eM0A@mail.gmail.com>
[not found] ` <186eb035-4bc4-ff72-ee41-aeb6d81888e3@redhat.com>
[not found] ` <X8T0E2qvF2cgADl+@kroah.com>
[not found] ` <dd557c38-a919-5e5e-ab3b-17a235f17139@redhat.com>
[not found] ` <20201130172004.GA966032@rowland.harvard.edu>
[not found] ` <abb0a79d-63a0-6f3d-4812-f828283cd47c@redhat.com>
[not found] ` <CAGnHSEk1GixNK71CJMymwLE=MyedjCkiG5Ubq1=O_wFxBBM0GQ@mail.gmail.com>
[not found] ` <CAGnHSEmPpbDokAfGkeCkvo3JuYfnosVt8H+TK7ZWFNsdyWAfYQ@mail.gmail.com>
2020-11-30 20:36 ` [PATCH 2/2] usb-storage: revert from scsi_add_host_with_dma() to scsi_add_host() Alan Stern
2021-02-25 16:35 ` Alan Stern
2021-02-26 5:53 ` Christoph Hellwig [this message]
2021-03-01 15:59 ` Alan Stern
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=20210226055352.GA2996@lst.de \
--to=hch@lst.de \
--cc=hdegoede@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=stern@rowland.harvard.edu \
--cc=tom.ty89@gmail.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