From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 728EBC47254 for ; Sat, 2 May 2020 18:12:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5708C20775 for ; Sat, 2 May 2020 18:12:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588443169; bh=Ur+zvGNhBRzpx5YCIfnkV/VY4X+PW2QlTOtRCvL2/rE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=TxD4tCk5YSHL2NGdQRYbCLDMLHggB26EDru6MJ10KhCqFDKjDadFU2bmtr2bSl1vz ahSTBzZWAiQNcdF5HqcY1OZ9zT6z/En7qmrLSCqqPGF2RM4ocschBr3//q4W0hd12U m7UJ4WRUH26A0QvOkxcKxT8aAmYnBavVzVQDgz78= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728370AbgEBSMs (ORCPT ); Sat, 2 May 2020 14:12:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:50298 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727997AbgEBSMs (ORCPT ); Sat, 2 May 2020 14:12:48 -0400 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D540E206CD; Sat, 2 May 2020 18:12:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588443166; bh=Ur+zvGNhBRzpx5YCIfnkV/VY4X+PW2QlTOtRCvL2/rE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=tp9mmQp6mmXP4vD22n6N4V9mEFSjQYrf1bCBdl3r42lLRHJ6v1VofGujO6mMZYb4m u879WlGm0ZXXHyL7N77Fkz9GyfvAIDRCMBPKRAGSSm0sP52E5vzrr0fRieRthWWllb vd5NHDSeOA47K4bS5yoFnddv0wnSv5G7K2a7msFQ= Date: Sat, 2 May 2020 19:12:42 +0100 From: Jonathan Cameron To: "Ardelean, Alexandru" Cc: "linux-kernel@vger.kernel.org" , "linux-iio@vger.kernel.org" , "lars@metafoo.de" Subject: Re: [RFC PATCH 1/4] iio: Move scan mask management to the core Message-ID: <20200502191242.310fa73d@archlinux> In-Reply-To: <9f8e44988909f6d26ad6b383ccead1f121594d5e.camel@analog.com> References: <20200424051818.6408-1-alexandru.ardelean@analog.com> <20200424051818.6408-2-alexandru.ardelean@analog.com> <20200426104538.657a2d9a@archlinux> <9f8e44988909f6d26ad6b383ccead1f121594d5e.camel@analog.com> X-Mailer: Claws Mail 3.17.5 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 27 Apr 2020 06:25:19 +0000 "Ardelean, Alexandru" wrote: > On Sun, 2020-04-26 at 10:45 +0100, Jonathan Cameron wrote: > > [External] > > > > On Fri, 24 Apr 2020 08:18:15 +0300 > > Alexandru Ardelean wrote: > > > > > From: Lars-Peter Clausen > > > > > > Let the core handle the buffer scan mask management including allocation > > > and channel selection. Having this handled in a central place rather than > > > open-coding it all over the place will make it easier to change the > > > implementation. > > > > > > Signed-off-by: Lars-Peter Clausen > > > Signed-off-by: Alexandru Ardelean > > > > Hi Alex, > > > > For some reason I only have patch 1 of this series of 4. > > > > This one looks reasonable to me as abstracts away how it is implemented > > which is good. A few comments and a question inline. > > > > Replies inline. > > Since the discussion about patches 3 & 4 got a little more complicated [than I'd > like to focus on at this point in time], would it be ok to split patches 1 & 2 > into a separate series? [after discussions are resolved] > Even just those 2 patches helps me work on 2 kernel trees [the ADI internal & > the IIO upstream one], as it minimizes the diff. > That would be fine. > > > Jonathan > > > > > > > --- > > > drivers/iio/buffer/industrialio-buffer-cb.c | 17 ++++------ > > > drivers/iio/industrialio-buffer.c | 36 +++++++++++++++------ > > > drivers/iio/inkern.c | 15 +++++++++ > > > include/linux/iio/consumer.h | 10 ++++++ > > > 4 files changed, 58 insertions(+), 20 deletions(-) > > > > > > diff --git a/drivers/iio/buffer/industrialio-buffer-cb.c > > > b/drivers/iio/buffer/industrialio-buffer-cb.c > > > index 47c96f7f4976..b50f1f48cac6 100644 > > > --- a/drivers/iio/buffer/industrialio-buffer-cb.c > > > +++ b/drivers/iio/buffer/industrialio-buffer-cb.c > > > @@ -33,8 +33,7 @@ static int iio_buffer_cb_store_to(struct iio_buffer > > > *buffer, const void *data) > > > static void iio_buffer_cb_release(struct iio_buffer *buffer) > > > { > > > struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer); > > > - > > > - bitmap_free(cb_buff->buffer.scan_mask); > > > + iio_buffer_free_scanmask(buffer); > > > kfree(cb_buff); > > > } > > > > > > @@ -72,27 +71,25 @@ struct iio_cb_buffer *iio_channel_get_all_cb(struct > > > device *dev, > > > } > > > > > > cb_buff->indio_dev = cb_buff->channels[0].indio_dev; > > > - cb_buff->buffer.scan_mask = bitmap_zalloc(cb_buff->indio_dev- > > > >masklength, > > > - GFP_KERNEL); > > > - if (cb_buff->buffer.scan_mask == NULL) { > > > - ret = -ENOMEM; > > > + > > > + ret = iio_buffer_alloc_scanmask(&cb_buff->buffer, cb_buff->indio_dev); > > > + if (ret) > > > goto error_release_channels; > > > - } > > > + > > > chan = &cb_buff->channels[0]; > > > while (chan->indio_dev) { > > > if (chan->indio_dev != cb_buff->indio_dev) { > > > ret = -EINVAL; > > > goto error_free_scan_mask; > > > } > > > - set_bit(chan->channel->scan_index, > > > - cb_buff->buffer.scan_mask); > > > + iio_buffer_channel_enable(&cb_buff->buffer, chan); > > > chan++; > > > } > > > > > > return cb_buff; > > > > > > error_free_scan_mask: > > > - bitmap_free(cb_buff->buffer.scan_mask); > > > + iio_buffer_free_scanmask(&cb_buff->buffer); > > > error_release_channels: > > > iio_channel_release_all(cb_buff->channels); > > > error_free_cb_buff: > > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio- > > > buffer.c > > > index 221157136af6..c06691281287 100644 > > > --- a/drivers/iio/industrialio-buffer.c > > > +++ b/drivers/iio/industrialio-buffer.c > > > @@ -206,6 +206,26 @@ void iio_buffer_init(struct iio_buffer *buffer) > > > } > > > EXPORT_SYMBOL(iio_buffer_init); > > > > > > +int iio_buffer_alloc_scanmask(struct iio_buffer *buffer, > > > + struct iio_dev *indio_dev) > > I'm not sure passing the indio_dev in here makes sense as it > > obscures that all we are getting from it is the masklength. > > May be better to pass that explicitly. > > Passing indio_dev seems to make more sense if we are also doing the channel_mask > thing in the next patches. > If we do the buffer->indio_dev back-ref, then we can just pass the buffer. > But that may obscure things a bit more about the 'masklength'; though, that may > be one of the intentions I suppose [can't be sure] > > > > > > +{ > > > + if (!indio_dev->masklength) > > > + return 0; > > > > This is a bit of an oddity of the old code. Any idea why we > > allow things to continue with a masklength of 0? Seems to me > > that it is thoroughly broken if that occurs! > > See [1] > > > > > > + > > > + buffer->scan_mask = bitmap_zalloc(indio_dev->masklength, GFP_KERNEL); > > > + if (buffer->scan_mask == NULL) > > > + return -ENOMEM; > > > + > > > + return 0; > > > +} > > > +EXPORT_SYMBOL_GPL(iio_buffer_alloc_scanmask); > > > + > > > +void iio_buffer_free_scanmask(struct iio_buffer *buffer) > > > +{ > > > + bitmap_free(buffer->scan_mask); > > > +} > > > +EXPORT_SYMBOL_GPL(iio_buffer_free_scanmask); > > > + > > > /** > > > * iio_buffer_set_attrs - Set buffer specific attributes > > > * @buffer: The buffer for which we are setting attributes > > > @@ -1301,14 +1321,10 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev > > > *indio_dev) > > > indio_dev->scan_index_timestamp = > > > channels[i].scan_index; > > > } > > > - if (indio_dev->masklength && buffer->scan_mask == NULL) { > > [1] I suspect when this patch was written, it had this part in mind [with the > retun 0] > So, it preserves behavior a bit. > The 'buffer->scan_mask == NULL' check is a bit odd; I wonder if the initial > intent was to also allow to pass a 'scan_mask' from somewhere else. > > So, updating '!indio_dev->masklength' to return -EINVAL in > iio_buffer_alloc_scanmask() sounds like a good idea, but I'll need to add a note > in the commit description. Yup. Sounds good. > > > > > - buffer->scan_mask = bitmap_zalloc(indio_dev->masklength, > > > - GFP_KERNEL); > > > - if (buffer->scan_mask == NULL) { > > > - ret = -ENOMEM; > > > - goto error_cleanup_dynamic; > > > - } > > > - } > > > + > > > + ret = iio_buffer_alloc_scanmask(buffer, indio_dev); > > > + if (ret) > > > + goto error_cleanup_dynamic; > > > } > > > > > > buffer->scan_el_group.name = iio_scan_elements_group_name; > > > @@ -1329,7 +1345,7 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev > > > *indio_dev) > > > return 0; > > > > > > error_free_scan_mask: > > > - bitmap_free(buffer->scan_mask); > > > + iio_buffer_free_scanmask(buffer); > > > error_cleanup_dynamic: > > > iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list); > > > kfree(indio_dev->buffer->buffer_group.attrs); > > > @@ -1342,7 +1358,7 @@ void iio_buffer_free_sysfs_and_mask(struct iio_dev > > > *indio_dev) > > > if (!indio_dev->buffer) > > > return; > > > > > > - bitmap_free(indio_dev->buffer->scan_mask); > > > + iio_buffer_free_scanmask(indio_dev->buffer); > > > kfree(indio_dev->buffer->buffer_group.attrs); > > > kfree(indio_dev->buffer->scan_el_group.attrs); > > > iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list); > > > diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c > > > index ede99e0d5371..f35cb9985edc 100644 > > > --- a/drivers/iio/inkern.c > > > +++ b/drivers/iio/inkern.c > > > @@ -11,6 +11,7 @@ > > > > > > #include > > > #include "iio_core.h" > > > +#include > > > #include > > > #include > > > #include > > > @@ -857,6 +858,20 @@ int iio_write_channel_raw(struct iio_channel *chan, int > > > val) > > > } > > > EXPORT_SYMBOL_GPL(iio_write_channel_raw); > > > > > > +void iio_buffer_channel_enable(struct iio_buffer *buffer, > > > + const struct iio_channel *chan) > > > +{ > > > + set_bit(chan->channel->scan_index, buffer->scan_mask); > > > +} > > > +EXPORT_SYMBOL_GPL(iio_buffer_channel_enable); > > > + > > > +void iio_buffer_channel_disable(struct iio_buffer *buffer, > > > + const struct iio_channel *chan) > > > +{ > > > + clear_bit(chan->channel->scan_index, buffer->scan_mask); > > > +} > > > +EXPORT_SYMBOL_GPL(iio_buffer_channel_disable); > > > + > > > unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan) > > > { > > > const struct iio_chan_spec_ext_info *ext_info; > > > diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h > > > index c4118dcb8e05..dbc87c26250a 100644 > > > --- a/include/linux/iio/consumer.h > > > +++ b/include/linux/iio/consumer.h > > > @@ -12,6 +12,7 @@ > > > > > > struct iio_dev; > > > struct iio_chan_spec; > > > +struct iio_buffer; > > > struct device; > > > > > > /** > > > @@ -342,6 +343,15 @@ int iio_read_channel_scale(struct iio_channel *chan, > > > int *val, > > > int iio_convert_raw_to_processed(struct iio_channel *chan, int raw, > > > int *processed, unsigned int scale); > > > > > > +void iio_buffer_channel_enable(struct iio_buffer *buffer, > > > + const struct iio_channel *chan); > > > +void iio_buffer_channel_disable(struct iio_buffer *buffer, > > > + const struct iio_channel *chan); > > > + > > > +int iio_buffer_alloc_scanmask(struct iio_buffer *buffer, > > > + struct iio_dev *indio_dev); > > > +void iio_buffer_free_scanmask(struct iio_buffer *buffer); > > > + > > > /** > > > * iio_get_channel_ext_info_count() - get number of ext_info attributes > > > * connected to the channel.