Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751659AbdCYSUP (ORCPT ); Sat, 25 Mar 2017 14:20:15 -0400 Received: from mail-vk0-f66.google.com ([209.85.213.66]:35351 "EHLO mail-vk0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751572AbdCYSUN (ORCPT ); Sat, 25 Mar 2017 14:20:13 -0400 MIME-Version: 1.0 In-Reply-To: <0a2934e9-5dca-1c2b-125d-776e9dfcfccb@kernel.org> References: <20170323092048.GA25470@singhal-Inspiron-5558> <0a2934e9-5dca-1c2b-125d-776e9dfcfccb@kernel.org> From: SIMRAN SINGHAL Date: Sat, 25 Mar 2017 23:49:16 +0530 Message-ID: Subject: Re: [PATCH v9] staging: iio: adis16060: Remove iio_dev mlock and refactor code To: Jonathan Cameron Cc: Lars-Peter Clausen , Michael Hennerich , Hartmut Knaack , Peter Meerwald-Stadler , Greg Kroah-Hartman , linux-iio@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, outreachy-kernel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4068 Lines: 113 On Sat, Mar 25, 2017 at 11:16 PM, Jonathan Cameron wrote: > On 23/03/17 09:20, simran singhal wrote: >> The IIO subsystem is redefining iio_dev->mlock to be used by >> the IIO core only for protecting device operating mode changes. >> ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes. >> >> In this driver, mlock was being used to protect hardware state changes. >> >> In the driver, buf_lock protects both the adis16060_spi_write() and >> adis16060_spi_read() functions and both are always called in pair. >> First write, then read. Refactor the code to have one single function >> adis16060_spi_write_then_read() protected by the buf_lock. This removes >> the need for additional locking via mlock, so this locking is removed. >> >> Signed-off-by: simran singhal > Unfortunately I've now pushed out v8 as togreg which is a non rebasing tree. > As such, could you post a separate patch, on top of that making the > than -> then change? > ok, I will send the patch with than-> then change. > Thanks, > > Jonathan >> --- >> >> v9: >> -Change the name of function from adis16060_spi_write_than_read() >> to adis16060_spi_write_then_read(). change "than" to "then" as >> its time depended. >> -Add mutex_unlock > As Alison keeps mentioning, ideal is to keep all previous change logs > here as it allows those who last looked at say v5 to know what changed > in between without reading a lot of threads! >> Sorry, will not repeate this in future. >> drivers/staging/iio/gyro/adis16060_core.c | 35 +++++++++---------------------- >> 1 file changed, 10 insertions(+), 25 deletions(-) >> >> diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c >> index c9d46e7..9675245 100644 >> --- a/drivers/staging/iio/gyro/adis16060_core.c >> +++ b/drivers/staging/iio/gyro/adis16060_core.c >> @@ -40,25 +40,20 @@ struct adis16060_state { >> >> static struct iio_dev *adis16060_iio_dev; >> >> -static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val) >> +static int adis16060_spi_write_then_read(struct iio_dev *indio_dev, >> + u8 conf, u16 *val) >> { >> int ret; >> struct adis16060_state *st = iio_priv(indio_dev); >> >> mutex_lock(&st->buf_lock); >> - st->buf[2] = val; /* The last 8 bits clocked in are latched */ >> + st->buf[2] = conf; /* The last 8 bits clocked in are latched */ >> ret = spi_write(st->us_w, st->buf, 3); >> - mutex_unlock(&st->buf_lock); >> - >> - return ret; >> -} >> - >> -static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val) >> -{ >> - int ret; >> - struct adis16060_state *st = iio_priv(indio_dev); >> >> - mutex_lock(&st->buf_lock); >> + if (ret < 0) { >> + mutex_unlock(&st->buf_lock); >> + return ret; >> + } >> >> ret = spi_read(st->us_r, st->buf, 3); >> >> @@ -86,17 +81,11 @@ static int adis16060_read_raw(struct iio_dev *indio_dev, >> >> switch (mask) { >> case IIO_CHAN_INFO_RAW: >> - /* Take the iio_dev status lock */ >> - mutex_lock(&indio_dev->mlock); >> - ret = adis16060_spi_write(indio_dev, chan->address); >> + ret = adis16060_spi_write_then_read(indio_dev, >> + chan->address, &tval); >> if (ret < 0) >> - goto out_unlock; >> + return ret; >> >> - ret = adis16060_spi_read(indio_dev, &tval); >> - if (ret < 0) >> - goto out_unlock; >> - >> - mutex_unlock(&indio_dev->mlock); >> *val = tval; >> return IIO_VAL_INT; >> case IIO_CHAN_INFO_OFFSET: >> @@ -110,10 +99,6 @@ static int adis16060_read_raw(struct iio_dev *indio_dev, >> } >> >> return -EINVAL; >> - >> -out_unlock: >> - mutex_unlock(&indio_dev->mlock); >> - return ret; >> } >> >> static const struct iio_info adis16060_info = { >> >