Re: [REVIEW] au0828-vbi.c

[Shuah Khan <shuahkh@osg.samsung.com>]

On 12/12/2014 02:42 AM, Hans Verkuil wrote:
> Hi Shuah,
> 
> This is my review for au0828-vbi.c with your patch applied.

Thanks. Will fix all of these.

-- Shuah
> 
>> /*
>>    au0828-vbi.c - VBI driver for au0828
>>
>>    Copyright (C) 2010 Devin Heitmueller <dheitmueller@kernellabs.com>
>>
>>    This work was sponsored by GetWellNetwork Inc.
>>
>>    This program is free software; you can redistribute it and/or modify
>>    it under the terms of the GNU General Public License as published by
>>    the Free Software Foundation; either version 2 of the License, or
>>    (at your option) any later version.
>>
>>    This program is distributed in the hope that it will be useful,
>>    but WITHOUT ANY WARRANTY; without even the implied warranty of
>>    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>    GNU General Public License for more details.
>>
>>    You should have received a copy of the GNU General Public License
>>    along with this program; if not, write to the Free Software
>>    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
>>    02110-1301, USA.
>>  */
>>
>> #include "au0828.h"
>>
>> #include <linux/kernel.h>
>> #include <linux/module.h>
>> #include <linux/init.h>
>> #include <linux/slab.h>
>>
>> static unsigned int vbibufs = 5;
>> module_param(vbibufs, int, 0644);
>> MODULE_PARM_DESC(vbibufs, "number of vbi buffers, range 2-32");
> 
> Drop this vbibufs argument. It's bogus.
> 
>>
>> /* ------------------------------------------------------------------ */
>>
>> static int vbi_queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
>> 			   unsigned int *nbuffers, unsigned int *nplanes,
>> 			   unsigned int sizes[], void *alloc_ctxs[])
>> {
>> 	struct au0828_dev *dev = vb2_get_drv_priv(vq);
>> 	unsigned long size;
>>
>> 	if (fmt)
>> 		size = fmt->fmt.pix.sizeimage;
> 
> It's a VBI format, so the size is
> 
> 	fmt->fmt.vbi.samples_per_line *
>                    (fmt->fmt.vbi.count[0] + fmt->fmt.vbi.count[1]);
> 
> 
>> 	else
>> 		size = dev->vbi_width * dev->vbi_height * 2;
>>
>> 	if (0 == *nbuffers)
>> 		*nbuffers = 32;
>> 	if (*nbuffers < 2)
>> 		*nbuffers = 2;
>> 	if (*nbuffers > 32)
>> 		*nbuffers = 32;
> 
> Remove these checks, they are not needed.
> 
> But if a fmt is passed in, then you *do* need to check if the new format size
> is enough to store the vbi data. If not, return -EINVAL.
> 
> Test with v4l2-compliance -V0 -s.
> 
>>
>> 	*nplanes = 1;
>> 	sizes[0] = size;
>>
>> 	return 0;
>> }
>>
>> static int vbi_buffer_prepare(struct vb2_buffer *vb)
>> {
>> 	struct au0828_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
>> 	struct au0828_buffer *buf = container_of(vb, struct au0828_buffer, vb);
>> 	unsigned long size;
>>
>> 	size = dev->vbi_width * dev->vbi_height * 2;
>>
>> 	if (vb2_plane_size(vb, 0) < size) {
>> 		pr_err("%s data will not fit into plane (%lu < %lu)\n",
>> 			__func__, vb2_plane_size(vb, 0), size);
>> 		return -EINVAL;
>> 	}
>> 	vb2_set_plane_payload(&buf->vb, 0, size);
>>
>> 	return 0;
>> }
>>
>> static void
>> vbi_buffer_queue(struct vb2_buffer *vb)
>> {
>> 	struct au0828_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
>> 	struct au0828_buffer *buf = container_of(vb, struct au0828_buffer, vb);
>> 	struct au0828_dmaqueue *vbiq = &dev->vbiq;
>> 	unsigned long flags = 0;
>>
>> 	buf->mem = vb2_plane_vaddr(vb, 0);
>> 	buf->length = vb2_plane_size(vb, 0);
>>
>> 	spin_lock_irqsave(&dev->slock, flags);
>> 	list_add_tail(&buf->list, &vbiq->active);
>> 	spin_unlock_irqrestore(&dev->slock, flags);
>> }
>>
>> struct vb2_ops au0828_vbi_qops = {
>> 	.queue_setup     = vbi_queue_setup,
>> 	.buf_prepare     = vbi_buffer_prepare,
>> 	.buf_queue       = vbi_buffer_queue,
>> 	.start_streaming = au0828_start_analog_streaming,
>> 	.stop_streaming  = au0828_stop_vbi_streaming,
>> 	.wait_prepare    = vb2_ops_wait_prepare,
>> 	.wait_finish     = vb2_ops_wait_finish,
>> };
> 
> Regards,
> 
> 	Hans
> 


-- 
Shuah Khan
Sr. Linux Kernel Developer
Samsung Open Source Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978