Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932634AbdCWHjl convert rfc822-to-8bit (ORCPT ); Thu, 23 Mar 2017 03:39:41 -0400 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:51788 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932484AbdCWHji (ORCPT ); Thu, 23 Mar 2017 03:39:38 -0400 Date: Thu, 23 Mar 2017 07:20:33 +0000 User-Agent: K-9 Mail for Android In-Reply-To: References: <20170322162042.GA7955@singhal-Inspiron-5558> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Subject: Re: [PATCH v8] staging: adis16060: Remove iio_dev mlock and refactor code To: simran singhal , lars@metafoo.de CC: Michael.Hennerich@analog.com, Hartmut Knaack , Peter Meerwald-Stadler , Greg Kroah-Hartman , linux-iio@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, outreachy-kernel@googlegroups.com From: Jonathan Cameron Message-ID: <2CEA8DF3-D55A-4CEC-AC6F-6B331726BEB3@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4587 Lines: 146 On 22 March 2017 19:22:20 GMT+00:00, Jonathan Cameron wrote: >On 22/03/17 16:20, 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_than_read() and remove >> the use of mlock as adis16060_read_raw() does not require an >> iio_dev->mlock for reads. >I'll slightly modify this description. The key thing is >that after the above change to have a unified read then write >there is no longer any need for mlock to protect these >read, update, write cycles. >> >> Signed-off-by: simran singhal >Applied to the togreg branch of iio.git and pushed out as testing >for the autobuilders to play with it. > >I slightly modified the title as well. It's useful to be a little >more specific than staging, so I added iio: after that. Another example of how the tests that 0day is doing are way better than my tired eyes at the end of a day... > >Thanks, > >Jonathan >> --- >> >> v8: >> -change subject >> -change commit message >> v7: >> -Change subject >> -Remove lock from read_raw instead from >> function adis16060_spi_write_than_read(). >> v6: >> -Change commit message >> -Remove nested lock >> v5: >> -Rename val in adis16060_spi_write_than_read() to conf. >> -Rename val2 in adis16060_spi_write_than_read() to val. >> -Corrected Checkpatch issues. >> -Removed goto from adis16060_read_raw(). >> v4: >> -Refactored code >> -change commit subject >> -change commit message >> v3: >> -Removed new lock to reuse the existing lock >> v2: >> -Fixed compilation error >> >> drivers/staging/iio/gyro/adis16060_core.c | 33 >++++++++----------------------- >> 1 file changed, 8 insertions(+), 25 deletions(-) >> >> diff --git a/drivers/staging/iio/gyro/adis16060_core.c >b/drivers/staging/iio/gyro/adis16060_core.c >> index c9d46e7..e96fce5 100644 >> --- a/drivers/staging/iio/gyro/adis16060_core.c >> +++ b/drivers/staging/iio/gyro/adis16060_core.c >> @@ -40,25 +40,18 @@ 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_than_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) Not unlocking buf_lock in this path. I will fix up later.... Jonathan >> + return ret; >> >> ret = spi_read(st->us_r, st->buf, 3); >> >> @@ -86,17 +79,11 @@ 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_than_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 +97,6 @@ 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 = { >> > >-- >To unsubscribe from this list: send the line "unsubscribe linux-iio" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html -- Sent from my Android device with K-9 Mail. Please excuse my brevity.