From: Alan Stern <stern@rowland.harvard.edu>
To: Christoph Hellwig <hch@lst.de>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
<gregkh@linuxfoundation.org>, <linux-usb@vger.kernel.org>,
<usb-storage@lists.one-eyed-alien.net>,
<linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH v2] usb-storage: Add a limitation for blk_queue_max_hw_sectors()
Date: Thu, 13 Jun 2019 13:21:47 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.4.44L0.1906131317210.1307-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <20190613171112.GA22155@lst.de>
On Thu, 13 Jun 2019, Christoph Hellwig wrote:
> On Thu, Jun 13, 2019 at 01:06:40PM -0400, Alan Stern wrote:
> > Hmmm. Would it be easier instead to copy the DMA mapping parameters
> > from us->pusb_dev->bus->sysdev into the SCSI host's parent before
> > calling scsi_add_host()? That way the correct values would be
> > available from the beginning, so the existing DMA setup would
> > automatically use the correct sizes.
>
> It would in theory. But at usb-storage has a special max_sectors quirk
> for tape devices, and as the device type is a per-LU property we'd
> still have to override it in ->slave_configure.
Not just for tape devices. But that's okay; those max_sectors
overrides have been present for a long time and we can keep them.
Getting rid of the virt_boundary_mask stuff would still be a big
improvement.
Alan Stern
next prev parent reply other threads:[~2019-06-13 17:21 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-13 9:36 [PATCH v2] usb-storage: Add a limitation for blk_queue_max_hw_sectors() Yoshihiro Shimoda
2019-06-13 17:06 ` Alan Stern
2019-06-13 17:11 ` Christoph Hellwig
2019-06-13 17:21 ` Alan Stern [this message]
2019-06-17 4:17 ` Yoshihiro Shimoda
2019-06-17 6:22 ` Christoph Hellwig
2019-07-02 10:07 ` Yoshihiro Shimoda
2019-07-02 13:49 ` Suwan Kim
2019-07-02 14:06 ` shuah
2019-07-02 14:28 ` Alan Stern
2019-07-03 3:10 ` Yoshihiro Shimoda
2019-07-03 14:19 ` Alan Stern
2019-07-04 10:37 ` Yoshihiro Shimoda
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