From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936579AbdAEKEr (ORCPT ); Thu, 5 Jan 2017 05:04:47 -0500 Received: from mx0b-001ae601.pphosted.com ([67.231.152.168]:48048 "EHLO mx0b-001ae601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751241AbdAEKEk (ORCPT ); Thu, 5 Jan 2017 05:04:40 -0500 Authentication-Results: ppops.net; spf=none smtp.mailfrom=ckeepax@opensource.wolfsonmicro.com Date: Thu, 5 Jan 2017 10:05:28 +0000 From: Charles Keepax To: Lee Jones CC: , Subject: Re: [PATCH 3/3] mfd: arizona: Use regmap_read_poll_timeout instead of hard coding it Message-ID: <20170105100528.GS1867@localhost.localdomain> References: <1483542655-19980-1-git-send-email-ckeepax@opensource.wolfsonmicro.com> <1483542655-19980-3-git-send-email-ckeepax@opensource.wolfsonmicro.com> <20170105080701.GJ24225@dell> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170105080701.GJ24225@dell> User-Agent: Mutt/1.5.23 (2014-03-12) X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1701050163 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 05, 2017 at 08:07:01AM +0000, Lee Jones wrote: > On Wed, 04 Jan 2017, Charles Keepax wrote: > > > arizona_poll_reg essentially hard-codes regmap_read_poll_timeout, this > > patch updates the implementation to use regmap_read_poll_timeout. We > > still keep arizona_poll_reg around as regmap_read_poll_timeout is a > > macro so rather than expand this for each caller keep it wrapped in > > arizona_poll_reg. > > > > Signed-off-by: Charles Keepax > > --- > > drivers/mfd/arizona-core.c | 28 +++++++++++----------------- > > 1 file changed, 11 insertions(+), 17 deletions(-) > > > > diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c > > index 4cb34c3..e6fae3c 100644 > > --- a/drivers/mfd/arizona-core.c > > +++ b/drivers/mfd/arizona-core.c > > @@ -236,28 +236,22 @@ static irqreturn_t arizona_overclocked(int irq, void *data) > > } > > > > static int arizona_poll_reg(struct arizona *arizona, > > - int timeout, unsigned int reg, > > + int npolls, unsigned int reg, > > unsigned int mask, unsigned int target) > > { > > + const int poll_us = 7500; > > Get rid of this and replace its usage with a nice #define describing > exactly what the timeout is for i.e what timed out. > I can replace this with a define if you prefer although since the value is only used locally I generally prefer a const variable as it keeps all the relevant code together. > ... okay, I just read the doc. This should really be 'SLEEP'. > > Where did 7500 come from anyway? Is it documented? > To be fair this number is a little pulled from my ... err the air. But basically provides a reasonable balance of timing between polls for the various users of the function. It didn't really seem worth having each user specify its own timing for this part as we generally don't care down to a couple of mS here or there. > > unsigned int val = 0; > > - int ret, i; > > - > > - for (i = 0; i < timeout; i++) { > > - ret = regmap_read(arizona->regmap, reg, &val); > > - if (ret != 0) { > > - dev_err(arizona->dev, "Failed to read reg 0x%x: %d\n", > > - reg, ret); > > - continue; > > - } > > - > > - if ((val & mask) == target) > > - return 0; > > + int ret; > > > > - usleep_range(1000, 5000); > > - } > > + ret = regmap_read_poll_timeout(arizona->regmap, > > + ARIZONA_INTERRUPT_RAW_STATUS_5, val, > > + ((val & mask) == target), poll_us, > > + npolls * poll_us); > > What's the relevance of npolls? Is this number documented, or was it > pulled from your ... err, the air? > Its an argument passed into the function, its called npolls in a function that polls a register I really don't know how to make the fact it is the number of polls to do any more clear than that. As for the number passed into the function that depends on how long that particular register should be polled for, this is a function that is used in several places for polling for a particular register state. Would all these issues perhaps be best solved by my adding some kernel doc for the function with some more description of what everything is? Thanks, Charles > > + if (ret) > > + dev_err(arizona->dev, "Polling reg 0x%x timed out: %x\n", > > + reg, val); > > > > - dev_err(arizona->dev, "Polling reg 0x%x timed out: %x\n", reg, val); > > - return -ETIMEDOUT; > > + return ret; > > } > > > > static int arizona_wait_for_boot(struct arizona *arizona) > > -- > Lee Jones > Linaro STMicroelectronics Landing Team Lead > Linaro.org │ Open source software for ARM SoCs > Follow Linaro: Facebook | Twitter | Blog