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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 29C23C388F9 for ; Sat, 21 Nov 2020 18:44:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DD35F2100A for ; Sat, 21 Nov 2020 18:44:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="rSvxAxHO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727171AbgKUSou (ORCPT ); Sat, 21 Nov 2020 13:44:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:50658 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726672AbgKUSou (ORCPT ); Sat, 21 Nov 2020 13:44:50 -0500 Received: from archlinux (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (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 ED71520867; Sat, 21 Nov 2020 18:44:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605984289; bh=Pw3yjazdRYfGLN04zKeb1ThaolM5swK0XcV1YK7oiVY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rSvxAxHO2qqYSnkTadedEtQcY9/Bf2NiQhcLMdN3S/aPKDdePFjvKqgUbji/iHH/a cMxvJpGqnZ30Uq2wvVZZvOfBFZZpI2sC7khNeN3GzW3V6l+UEY7Q8HNu58ZbtGo7Dx TbUL9/12G8lxymaBE7ciTsCNt005A7rrqN0fTlNU= Date: Sat, 21 Nov 2020 18:44:45 +0000 From: Jonathan Cameron To: Alexandru Ardelean Cc: , , Subject: Re: [RFC PATCH 11/12] iio: buffer: introduce support for attaching more IIO buffers Message-ID: <20201121184445.12ec2d92@archlinux> In-Reply-To: <20201117162340.43924-12-alexandru.ardelean@analog.com> References: <20201117162340.43924-1-alexandru.ardelean@analog.com> <20201117162340.43924-12-alexandru.ardelean@analog.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Tue, 17 Nov 2020 18:23:39 +0200 Alexandru Ardelean wrote: > With this change, calling iio_device_attach_buffer() will actually attach > more buffers. > Right now this doesn't do any validation of whether a buffer is attached > twice; maybe that can be added later (if needed). Attaching a buffer more > than once should yield noticeably bad results. > > The first buffer is the legacy buffer, so a reference is kept to it. > > At this point, accessing the data for the extra buffers (that are added > after the first one) isn't possible yet. > > Signed-off-by: Alexandru Ardelean A couple of minor things in here.. Jonathan > --- > drivers/iio/industrialio-buffer.c | 58 +++++++++++++++++++++++++------ > include/linux/iio/buffer_impl.h | 3 ++ > include/linux/iio/iio-opaque.h | 4 +++ > 3 files changed, 54 insertions(+), 11 deletions(-) > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > index c83cec89eddf..daa68822cea7 100644 > --- a/drivers/iio/industrialio-buffer.c > +++ b/drivers/iio/industrialio-buffer.c > @@ -1513,6 +1513,7 @@ static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer); > > int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > { > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > struct iio_buffer *buffer = indio_dev->buffer; > const struct iio_chan_spec *channels; > int i, ret; > @@ -1529,15 +1530,18 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > if (!buffer) > return 0; > > - ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, 0); > - if (ret) > - return ret; > + for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) { > + buffer = iio_dev_opaque->attached_buffers[i]; > + ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, i); > + if (ret) > + goto error_unwind_sysfs_and_mask; > + } > > ret = sysfs_create_link(&indio_dev->dev.kobj, > &indio_dev->buffer->buffer_dir, > "buffer"); > if (ret) > - goto error_free_sysfs_and_mask; > + goto error_unwind_sysfs_and_mask; > > ret = sysfs_create_link(&indio_dev->dev.kobj, > &indio_dev->buffer->scan_el_dir, > @@ -1549,8 +1553,14 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > > error_remove_buffer_dir_link: > sysfs_remove_link(&indio_dev->dev.kobj, "buffer"); > -error_free_sysfs_and_mask: > - __iio_buffer_free_sysfs_and_mask(buffer); > + i = iio_dev_opaque->attached_buffers_cnt - 1; Perhaps just use a counter variable that is only for this then you won't need to set it again in this error path. > +error_unwind_sysfs_and_mask: > + for (; i >= 0; i--) { > + buffer = iio_dev_opaque->attached_buffers[i]; > + __iio_buffer_free_sysfs_and_mask(buffer); > + } > + kfree(iio_dev_opaque->attached_buffers); > + iio_dev_opaque->attached_buffers = NULL; > return ret; > } > > @@ -1568,7 +1578,9 @@ static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) > > void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) > { > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > struct iio_buffer *buffer = indio_dev->buffer; > + int i; > > if (!buffer) > return; > @@ -1576,7 +1588,13 @@ void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) > sysfs_remove_link(&indio_dev->dev.kobj, "scan_elements"); > sysfs_remove_link(&indio_dev->dev.kobj, "buffer"); > > - __iio_buffer_free_sysfs_and_mask(buffer); > + for (i = iio_dev_opaque->attached_buffers_cnt - 1; i >= 0; i--) { > + buffer = iio_dev_opaque->attached_buffers[i]; > + __iio_buffer_free_sysfs_and_mask(buffer); > + } > + > + kfree(iio_dev_opaque->attached_buffers); > + iio_dev_opaque->attached_buffers = NULL; > } > > /** > @@ -1709,14 +1727,32 @@ EXPORT_SYMBOL_GPL(iio_buffer_get_iio_dev); > * @buffer: The buffer to attach to the device > * > * This function attaches a buffer to a IIO device. The buffer stays attached to > - * the device until the device is freed. The function should only be called at > - * most once per device. > + * the device until the device is freed. For legacy reasons, the first attached > + * buffer will also be assigned to 'indio_dev->buffer'. > */ > void iio_device_attach_buffer(struct iio_dev *indio_dev, > struct iio_buffer *buffer) > { > - indio_dev->buffer = iio_buffer_get(buffer); > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > + struct iio_buffer **new, **old = iio_dev_opaque->attached_buffers; > + unsigned int cnt = iio_dev_opaque->attached_buffers_cnt; > + > + cnt++; > + > + new = krealloc(old, sizeof(*new) * cnt, GFP_KERNEL); > + if (!new) { > + kfree(old); Need a comment on why freeing old makes sense. > + return; > + } > + iio_dev_opaque->attached_buffers = new; > + > + /* first buffer is legacy; attach it to the IIO device directly */ > + if (!indio_dev->buffer) > + indio_dev->buffer = iio_buffer_get(buffer); > + > + buffer->indio_dev = indio_dev; > > - indio_dev->buffer->indio_dev = indio_dev; > + iio_dev_opaque->attached_buffers[cnt - 1] = buffer; > + iio_dev_opaque->attached_buffers_cnt = cnt; > } > EXPORT_SYMBOL_GPL(iio_device_attach_buffer); > diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h > index 77e169e51434..e25d26a7f601 100644 > --- a/include/linux/iio/buffer_impl.h > +++ b/include/linux/iio/buffer_impl.h > @@ -124,6 +124,9 @@ struct iio_buffer { > /* @demux_bounce: Buffer for doing gather from incoming scan. */ > void *demux_bounce; > > + /* @attached_entry: Entry in the devices list of buffers attached by the driver. */ > + struct list_head attached_entry; > + > /* @buffer_list: Entry in the devices list of current buffers. */ > struct list_head buffer_list; > > diff --git a/include/linux/iio/iio-opaque.h b/include/linux/iio/iio-opaque.h > index 07c5a8e52ca8..1db0ea09520e 100644 > --- a/include/linux/iio/iio-opaque.h > +++ b/include/linux/iio/iio-opaque.h > @@ -7,6 +7,8 @@ > * struct iio_dev_opaque - industrial I/O device opaque information > * @indio_dev: public industrial I/O device information > * @event_interface: event chrdevs associated with interrupt lines > + * @attached_buffers: array of buffers statically attached by the driver > + * @attached_buffers_cnt: number of buffers in the array of statically attached buffers > * @buffer_list: list of all buffers currently attached > * @channel_attr_list: keep track of automatically created channel > * attributes > @@ -20,6 +22,8 @@ > struct iio_dev_opaque { > struct iio_dev indio_dev; > struct iio_event_interface *event_interface; > + struct iio_buffer **attached_buffers; > + unsigned int attached_buffers_cnt; > struct list_head buffer_list; > struct list_head channel_attr_list; > struct attribute_group chan_attr_group;