From: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
To: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Cc: "Jürgen Urban" <JuergenUrban-Mmb7MZpHnFY@public.gmane.org>,
"Fredrik Noring" <noring-zgYzP9v7iJcdnm+yROfE0A@public.gmane.org>,
"Christoph Hellwig" <hch-jcswGhMUV9g@public.gmane.org>,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Subject: Re: WARN_ON(irqs_disabled()) in dma_free_attrs?
Date: Fri, 2 Mar 2018 22:47:46 +0100 [thread overview]
Message-ID: <20180302214746.GA30506@lst.de> (raw)
In-Reply-To: <bfe85e97-2974-06ee-8c6d-f8e8a83348ea-5wv7dgnIgG8@public.gmane.org>
On Fri, Mar 02, 2018 at 07:55:48PM +0000, Robin Murphy wrote:
> On the other hand, HCD_LOCAL_MEM implies a per-device coherent pool. Since
> those bypass the arch-specific code, then depending on how unlikely we
> think it is for devices covered by a single driver to exist both with and
> without their own memory then it *might* also be reasonable to make the
> change below. Christoph, what do you reckon?
For the case where the coherent pool really is per-device this looks
technically ok. But it would also cover cases like arm nommu where
we have a single global nommu pool and we wouldn't warn for a driver
that frees with irqs disabled.
That being said I think allowing coherent frees from irqs disabled
context is a very bad idea to do in general, so if we can at all I'd
rather fix the driver than lifting any restrictions.
next prev parent reply other threads:[~2018-03-02 21:47 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-02 18:07 WARN_ON(irqs_disabled()) in dma_free_attrs? Fredrik Noring
[not found] ` <20180302180704.GA3846-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2018-03-02 19:55 ` Robin Murphy
[not found] ` <bfe85e97-2974-06ee-8c6d-f8e8a83348ea-5wv7dgnIgG8@public.gmane.org>
2018-03-02 21:47 ` Christoph Hellwig [this message]
2018-03-03 7:58 ` Fredrik Noring
2018-03-02 21:37 ` Christoph Hellwig
[not found] ` <20180302213711.GA30356-jcswGhMUV9g@public.gmane.org>
2018-03-03 8:22 ` Fredrik Noring
[not found] ` <20180303082234.GB24991-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2018-03-03 16:12 ` Christoph Hellwig
[not found] ` <20180303161249.GA9516-jcswGhMUV9g@public.gmane.org>
2018-03-03 18:19 ` Fredrik Noring
[not found] ` <20180303181904.GA19076-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2018-03-04 15:58 ` Alan Stern
[not found] ` <Pine.LNX.4.44L0.1803041054540.13805-100000-pYrvlCTfrz9XsRXLowluHWD2FQJk+8+b@public.gmane.org>
2018-03-04 17:59 ` Fredrik Noring
[not found] ` <20180304175949.GB2368-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2018-03-05 2:05 ` Alan Stern
2018-03-05 15:10 ` Christoph Hellwig
[not found] ` <20180305151010.GA15965-jcswGhMUV9g@public.gmane.org>
2018-03-11 18:01 ` Fredrik Noring
[not found] ` <20180311180124.GA27731-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2018-03-13 12:11 ` Robin Murphy
[not found] ` <5696e17e-e0f4-4e6c-7783-4eeea0ff7a5e-5wv7dgnIgG8@public.gmane.org>
2018-03-13 13:17 ` Christoph Hellwig
[not found] ` <20180313131745.GC6260-jcswGhMUV9g@public.gmane.org>
2018-03-14 17:43 ` Robin Murphy
[not found] ` <d0659e5e-4be7-9a1e-fb8e-b418962d74de-5wv7dgnIgG8@public.gmane.org>
2018-03-15 7:58 ` Christoph Hellwig
[not found] ` <20180315075831.GB12136-jcswGhMUV9g@public.gmane.org>
2018-03-15 13:11 ` Robin Murphy
[not found] ` <dfc5505e-9ab9-2d81-2fc5-623730a68ba9-5wv7dgnIgG8@public.gmane.org>
2018-06-22 14:56 ` Fredrik Noring
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