On Wed, Apr 20, 2011 at 4:59 PM, Daniel Glöckner <daniel...@gmx.net> wrote:
> On Wed, Apr 20, 2011 at 02:02:41PM +0800, Bob Liu wrote:
>> ---------- Forwarded message ----------
>
> Forwarding broke tabs.
>
Hi, Daniel
Thanks for your review, I will make a new patch later.
>> @@ -445,6 +446,20 @@ int uvc_queue_mmap(struct uvc_video_queue *queue,
>> struct vm_area_struct *vma)
>> addr += PAGE_SIZE;
>> size -= PAGE_SIZE;
>> }
>> +#else
>> + if (i == queue->count ||
>> + PAGE_ALIGN(size) != queue->buf_size) {
>
> Why do you need to round up size on nommu?
>
If didn't round up, it always return -EINVAL.
I don't know why config-mmu doesn't have this problem.
I use luvcview for testing and added some print, you can see that size
always != queue->buf_size.
So we need round up.
root:/> luvcview -f yuv -s 320x240 -i 30
luvcview 0.2.4
SDL information:
Video driver: fbcon
Hardware surfaces are available (382k video memory)
Device information:
Device path: /dev/video0
Stream settings:
Frame format: YUYV
Frame size: 320x240
Fsaiz e tis 03x2f5800, align size is 0x26000, bufsize is 0x26000
size is 0x25800, align size is 0x26000, bufsize is 0x26000
Unable to map buffer: Invalid argument
Init v4L2 failed !! exit fatal
root:/>
>> + ret = -EINVAL;
>> + goto done;
>> + }
>> +
>> + /* documentation/nommu-mmap.txt */
>
> I don't see where Documentation/nommu-mmap.txt provides any information
> on the following line(s).
>
I will rm it, sorry for that.
>> + vma->vm_flags |= VM_IO | VM_MAYSHARE;
>> +
>> + addr = (unsigned long)queue->mem + buffer->buf.m.offset;
>> + vma->vm_start = addr;
>> + vma->vm_end = addr + queue->buf_size;
>
> You don't need to do this here. vm_start and vm_end have already been
> modified like this by do_mmap_pgoff after get_unmapped_area had been
> called.
>
will rm also.
>> +#endif
>>
>> vma->vm_ops = &uvc_vm_ops;
>> vma->vm_private_data = buffer;
>> @@ -489,6 +504,38 @@ done:
>> }
>>
>> /*
>> + * Get unmapped area.
>> + *
>> + * NO-MMU arch need this function to make mmap() work correctly.
>> + */
>> +unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
>> + unsigned long addr, unsigned long len, unsigned long pgoff)
>> +{
>> + struct uvc_buffer *buffer;
>> + unsigned int i;
>> + int ret = 0;
>
> ret should be an unsigned long. You later try to store a pointer in
> there.
>
okay.
>> +
>> + mutex_lock(&queue->mutex);
>> + for (i = 0; i < queue->count; ++i) {
>> + buffer = &queue->buffer[i];
>> + if ((buffer->buf.m.offset >> PAGE_SHIFT) == pgoff)
>> + break;
>> + }
>> +
>> + if (i == queue->count ||
>> + PAGE_ALIGN(len) != queue->buf_size) {
>> + ret = -EINVAL;
>> + goto done;
>> + }
>> +
>> + addr = (unsigned long)queue->mem + buffer->buf.m.offset;
>> + ret = addr;
>> +done:
>> + mutex_unlock(&queue->mutex);
>> + return ret;
>> +}
>> +
>> +/*
>> * Enable or disable the video buffers queue.
>> *
>> * The queue must be enabled before starting video acquisition and must be
>> diff --git a/drivers/media/video/uvc/uvc_v4l2.c
>> b/drivers/media/video/uvc/uvc_v4l2.c
>> index 9005a8d..9efab61 100644
>> --- a/drivers/media/video/uvc/uvc_v4l2.c
>> +++ b/drivers/media/video/uvc/uvc_v4l2.c
>> @@ -1081,6 +1081,18 @@ static unsigned int uvc_v4l2_poll(struct file
>> *file, poll_table *wait)
>> return uvc_queue_poll(&stream->queue, file, wait);
>> }
>>
>> +static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
>> + unsigned long addr, unsigned long len, unsigned long pgoff,
>> + unsigned long flags)
>> +{
>> + struct uvc_fh *handle = file->private_data;
>> + struct uvc_streaming *stream = handle->stream;
>> +
>> + uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_get_unmapped_area\n");
>> +
>> + return uvc_queue_get_unmapped_area(&stream->queue, addr, len, pgoff);
>> +}
>> +
>> const struct v4l2_file_operations uvc_fops = {
>> .owner = THIS_MODULE,
>> .open = uvc_v4l2_open,
>> @@ -1089,5 +1101,6 @@ const struct v4l2_file_operations uvc_fops = {
>> .read = uvc_v4l2_read,
>> .mmap = uvc_v4l2_mmap,
>> .poll = uvc_v4l2_poll,
>> + .get_unmapped_area = uvc_v4l2_get_unmapped_area,
>> };
>>
>> diff --git a/drivers/media/video/uvc/uvcvideo.h
>> b/drivers/media/video/uvc/uvcvideo.h
>> index 45f01e7..48a2378 100644
>> --- a/drivers/media/video/uvc/uvcvideo.h
>> +++ b/drivers/media/video/uvc/uvcvideo.h
>> @@ -580,6 +580,12 @@ extern int uvc_queue_mmap(struct uvc_video_queue *queue,
>> struct vm_area_struct *vma);
>> extern unsigned int uvc_queue_poll(struct uvc_video_queue *queue,
>> struct file *file, poll_table *wait);
>> +#ifdef CONFIG_MMU
>> +#define uvc_queue_get_unmapped_area NULL
>> +#else
>> +extern unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue
>> *queue,
>> + unsigned long addr, unsigned long len, unsigned long pgoff);
>> +#endif
>> extern int uvc_queue_allocated(struct uvc_video_queue *queue);
>> static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
>> {
>> diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
>
> Rest looks good.
> Did you change anything in the generic code or is this a plain
> git revert c29fcff3daafbf46d64a543c1950bbd206ad8c1c
> ?
>
It's not a simple revert, I added uvc_v4l2_get_unmapped_area().
> Maybe one can unify the mmu and nommu versions of uvc_queue_mmap by using
> remap_vmalloc_range but IMHO the nommu versions of the remap_*_range
> functions are broken and should only validate if the source and destination
> addresses match.
>
Maybe we can try in future.
Thanks!
--
Regards,
--Bob
--
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