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From: Sinan Kaya <okaya@codeaurora.org>
To: Timur Tabi <timur@codeaurora.org>, Arnd Bergmann <arnd@arndb.de>
Cc: dmaengine@vger.kernel.org, cov@codeaurora.org, jcm@redhat.com,
	Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Ian Campbell <ijc+devicetree@hellion.org.uk>,
	Kumar Gala <galak@codeaurora.org>,
	Vinod Koul <vinod.koul@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver
Date: Sun, 1 Nov 2015 15:27:06 -0500	[thread overview]
Message-ID: <5636759A.4040506@codeaurora.org> (raw)
In-Reply-To: <56367433.60806@codeaurora.org>



On 11/1/2015 3:21 PM, Timur Tabi wrote:
> Sinan Kaya wrote:
>> However, after issuing the command; I still need to wait some amount of
>> time until hardware acknowledges the commands like reset/enable/disable.
>> These are relatively faster operations happening in microseconds. That's
>> why, I have mdelay there.
>
> Can you use readl_poll_timeout()?
>
Yes, I'm changing them to readl_poll_timeout after looking at the 
workqueue vs. expected delay requirements. I decided to stick with 
polled read.

First, I missed the point here that mdelay is discouraged.
https://www.kernel.org/doc/Documentation/timers/timers-howto.txt

According to same document, msleep can sleep up to 20ms which is not 
what I want.

This code is trying to sleep 10ms maximum and treating longer durations 
as failures.

readl_poll_timeout calls usleep_range that seems to satisfy what I'm 
looking for.

-- 
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a 
Linux Foundation Collaborative Project

  reply	other threads:[~2015-11-01 20:27 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-30  3:08 [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver Sinan Kaya
2015-10-30  3:08 ` [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Sinan Kaya
2015-10-30  8:01   ` kbuild test robot
2015-10-30  8:07   ` kbuild test robot
2015-10-30 10:24   ` Arnd Bergmann
2015-10-30 21:42     ` Sinan Kaya
2015-10-30 21:55       ` Timur Tabi
2015-10-30 22:47         ` Arnd Bergmann
2015-10-30 22:28       ` Arnd Bergmann
2015-10-30 22:36         ` Timur Tabi
2015-10-30 22:50           ` Arnd Bergmann
2015-10-31  1:53         ` Sinan Kaya
2015-11-01 18:50         ` Sinan Kaya
2015-11-01 20:21           ` Timur Tabi
2015-11-01 20:27             ` Sinan Kaya [this message]
2015-11-02 16:33           ` Arnd Bergmann
2015-11-02 19:21             ` Sinan Kaya
2015-11-02 20:55               ` Arnd Bergmann
2015-11-03  5:29                 ` Sinan Kaya
2015-11-03 10:43                   ` Arnd Bergmann
2015-11-03 21:07                     ` Sinan Kaya
2015-11-03 21:10                       ` Arnd Bergmann
2015-10-30 14:50   ` Mark Rutland
2015-10-31  4:27     ` Sinan Kaya
2015-10-30  4:34 ` [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver kbuild test robot
2015-10-30  4:34 ` [PATCH] dma: fix platform_no_drv_owner.cocci warnings kbuild test robot
2015-10-30  9:34 ` [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver Arnd Bergmann
2015-10-31  6:51   ` Sinan Kaya
2015-10-31 12:53     ` Timur Tabi
2015-10-31 12:53     ` Timur Tabi
2015-11-02 21:30     ` Arnd Bergmann
2015-11-03  4:45       ` Sinan Kaya
2015-11-03 12:42         ` Arnd Bergmann
2015-11-03 14:26           ` Timur Tabi
2015-11-04  1:04           ` Sinan Kaya
2015-10-30 15:00 ` Mark Rutland
2015-10-30 17:59   ` Andy Shevchenko
2015-10-30 18:08     ` Sinan Kaya
2015-10-30 18:18       ` Mark Rutland
2015-10-30 18:18       ` Andy Shevchenko
2015-10-30 18:25         ` Mark Rutland
2015-10-30 18:40           ` Andy Shevchenko
2015-10-30 18:48             ` Sinan Kaya
2015-10-30 19:01               ` Mark Rutland
2015-10-30 20:08                 ` Al Stone
2015-10-30 20:15                   ` Andy Shevchenko
2015-10-30 20:18                     ` Mark Rutland
2015-10-31  3:33                     ` Jon Masters
2015-10-31 17:34                       ` Sinan Kaya
2015-10-30 19:36           ` Sinan Kaya
2015-10-31 17:11   ` Sinan Kaya

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