From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Noam Liron <lnoam@marvell.com>
Cc: "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
Yuval Shaia <yshaia@marvell.com>
Subject: Re: [EXT] Re: Enforce USB DMA allocations to specific range
Date: Thu, 11 Feb 2021 10:02:42 +0100 [thread overview]
Message-ID: <YCTysiR4awtVPtMb@kroah.com> (raw)
In-Reply-To: <BYAPR18MB2741B58F5907F65C71ACF966B98C9@BYAPR18MB2741.namprd18.prod.outlook.com>
A: http://en.wikipedia.org/wiki/Top_post
Q: Were do I find info about this thing called top-posting?
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
A: No.
Q: Should I include quotations after my reply?
http://daringfireball.net/2007/07/on_top
On Thu, Feb 11, 2021 at 08:38:40AM +0000, Noam Liron wrote:
> Hi Greg,
>
> I am writing you again on the below subject, as I would like to get a
> "high level" opinion, and you are probably the most experienced ...
I am not a DMA expert at all, why not ask the dma developers instead?
> As I wrote below, I cannot rely on the DMA mask, as some USB
> allocation are not affected by it.
Why "some" and not "others"? Perhaps you need to fix your platform code
to prevent that from happening instead? Why is USB unique here?
> I thought of using private DMA pool that will be allocated where I
> need it (at the start of physical memory). However, this means adding
> specific ASIC code, which is less elegant.
> Do you think that's the right way?
I do not know your platform, only you do.
But I do think you should not be doing new development on 4.14, as that
is a very old and obsolete kernel and the dma code in the kernel has
changed a lot since 2017.
good luck!
greg k-h
next prev parent reply other threads:[~2021-02-11 9:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-28 13:54 Enforce USB DMA allocations to specific range Noam Liron
2020-12-28 14:18 ` Greg KH
2020-12-28 15:18 ` [EXT] " Noam Liron
2021-02-11 8:38 ` Noam Liron
2021-02-11 9:02 ` Greg Kroah-Hartman [this message]
2021-02-11 16:00 ` Alan Stern
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