From: Adrian Hunter <adrian.hunter@nokia.com>
To: Paul Walmsley <paul@pwsan.com>
Cc: "Ujfalusi Peter (Nokia-MS/Tampere)" <peter.ujfalusi@nokia.com>,
Tony Lindgren <tony@atomide.com>,
"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
Jarkko Nikula <jhnikula@gmail.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
Russell King <rmk+kernel@arm.linux.org.uk>
Subject: Re: [PATCH v5 2/3] OMAP3: DMA: Errata i541: sDMA FIFO draining does not finish
Date: Thu, 11 Nov 2010 09:17:18 +0200 [thread overview]
Message-ID: <4CDB987E.2020806@nokia.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1011101628410.28301@utopia.booyaka.com>
On 11/11/10 01:30, ext Paul Walmsley wrote:
> Hello Adrian,
>
> On Wed, 10 Nov 2010, Adrian Hunter wrote:
>
>> On 05/10/10 09:45, Peter Ujfalusi wrote:
>>
>>> + if (cpu_is_omap34xx()&& (l& OMAP_DMA_CCR_SEL_SRC_DST_SYNC)) {
>>> + int i = 0;
>>> + u32 sys_cf;
>>> +
>>> + /* Configure No-Standby */
>>> + l = dma_read(OCP_SYSCONFIG);
>>> + sys_cf = l;
>>> + l&= ~DMA_SYSCONFIG_MIDLEMODE_MASK;
>>> + l |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
>>> + dma_write(l , OCP_SYSCONFIG);
>>
>> Are accesses of OCP_SYSCONFIG synchronised?
>
> Do you mean, with respect to later reads and writes from the SDMA device?
> If so, then yes, later reads and writes to the SDMA are guaranteed to
> complete in order. But perhaps I am misunderstanding what you mean?
I just meant it looks racy e.g. two threads call omap_dma_stop() (or
another function that changes OCP_SYSCONFIG) at the same time
WARNING: multiple messages have this Message-ID (diff)
From: adrian.hunter@nokia.com (Adrian Hunter)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v5 2/3] OMAP3: DMA: Errata i541: sDMA FIFO draining does not finish
Date: Thu, 11 Nov 2010 09:17:18 +0200 [thread overview]
Message-ID: <4CDB987E.2020806@nokia.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1011101628410.28301@utopia.booyaka.com>
On 11/11/10 01:30, ext Paul Walmsley wrote:
> Hello Adrian,
>
> On Wed, 10 Nov 2010, Adrian Hunter wrote:
>
>> On 05/10/10 09:45, Peter Ujfalusi wrote:
>>
>>> + if (cpu_is_omap34xx()&& (l& OMAP_DMA_CCR_SEL_SRC_DST_SYNC)) {
>>> + int i = 0;
>>> + u32 sys_cf;
>>> +
>>> + /* Configure No-Standby */
>>> + l = dma_read(OCP_SYSCONFIG);
>>> + sys_cf = l;
>>> + l&= ~DMA_SYSCONFIG_MIDLEMODE_MASK;
>>> + l |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
>>> + dma_write(l , OCP_SYSCONFIG);
>>
>> Are accesses of OCP_SYSCONFIG synchronised?
>
> Do you mean, with respect to later reads and writes from the SDMA device?
> If so, then yes, later reads and writes to the SDMA are guaranteed to
> complete in order. But perhaps I am misunderstanding what you mean?
I just meant it looks racy e.g. two threads call omap_dma_stop() (or
another function that changes OCP_SYSCONFIG) at the same time
next prev parent reply other threads:[~2010-11-11 7:17 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-05 6:45 [PATCH v5 0/3] OMAP2/3: DMA: FIFO drain errata fixes Peter Ujfalusi
2010-10-05 6:45 ` Peter Ujfalusi
2010-10-05 6:45 ` [PATCH v5 1/3] omap: dma: Fix buffering disable bit setting for omap24xx Peter Ujfalusi
2010-10-05 6:45 ` Peter Ujfalusi
2010-10-05 9:41 ` G, Manjunath Kondaiah
2010-10-05 9:41 ` G, Manjunath Kondaiah
2010-10-05 6:45 ` [PATCH v5 2/3] OMAP3: DMA: Errata i541: sDMA FIFO draining does not finish Peter Ujfalusi
2010-10-05 6:45 ` Peter Ujfalusi
2010-11-10 13:46 ` Adrian Hunter
2010-11-10 13:46 ` Adrian Hunter
2010-11-10 13:52 ` Adrian Hunter
2010-11-10 13:52 ` Adrian Hunter
2010-11-10 23:30 ` Paul Walmsley
2010-11-10 23:30 ` Paul Walmsley
2010-11-11 7:17 ` Adrian Hunter [this message]
2010-11-11 7:17 ` Adrian Hunter
2010-10-05 6:45 ` [PATCH v5 3/3] OMAP: DMA: Use flags for errata handling Peter Ujfalusi
2010-10-05 6:45 ` Peter Ujfalusi
2010-10-05 9:55 ` [PATCH v5 0/3] OMAP2/3: DMA: FIFO drain errata fixes G, Manjunath Kondaiah
2010-10-05 9:55 ` G, Manjunath Kondaiah
2010-10-05 18:15 ` Tony Lindgren
2010-10-05 18:15 ` Tony Lindgren
2010-10-08 22:17 ` Tony Lindgren
2010-10-08 22:17 ` Tony Lindgren
2010-10-21 10:05 ` Peter Ujfalusi
2010-10-21 10:05 ` Peter Ujfalusi
2010-11-05 21:29 ` Tony Lindgren
2010-11-05 21:29 ` Tony Lindgren
2010-12-07 19:45 ` Greg KH
2010-12-07 19:45 ` Greg KH
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=4CDB987E.2020806@nokia.com \
--to=adrian.hunter@nokia.com \
--cc=jhnikula@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-omap@vger.kernel.org \
--cc=paul@pwsan.com \
--cc=peter.ujfalusi@nokia.com \
--cc=rmk+kernel@arm.linux.org.uk \
--cc=tony@atomide.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.