diff options
| author | Ian Armstrong <ian@iarmst.co.uk> | 2008-05-12 11:53:10 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-07-20 07:05:57 -0300 |
| commit | 4cbeb3711481a7e563fe4c61888986c4aa1cb22e (patch) | |
| tree | b672ed149fb8fe2544867f7d8b883df67814e7ac | |
| parent | 5a4f5da6552e6c55eff6fbddfee3eab908325c63 (diff) | |
V4L/DVB (7886): ivtvfb: Use DMA for write()
write() operations to the ivtv framebuffer will now attempt to use DMA if the
amount of data to copy is >= 4096 bytes. This change effectively depreciates
the need for the proprietary IVTVFB_IOC_DMA_FRAME ioctl since a write() of
sufficient size will do the same thing.
Signed-off-by: Ian Armstrong <ian@iarmst.demon.co.uk>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
| -rw-r--r-- | drivers/media/video/ivtv/ivtvfb.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/drivers/media/video/ivtv/ivtvfb.c b/drivers/media/video/ivtv/ivtvfb.c index 73be154f7f0..e8dbee44394 100644 --- a/drivers/media/video/ivtv/ivtvfb.c +++ b/drivers/media/video/ivtv/ivtvfb.c @@ -367,6 +367,87 @@ static int ivtvfb_prep_frame(struct ivtv *itv, int cmd, void __user *source, return ivtvfb_prep_dec_dma_to_device(itv, dest_offset, source, count); } +static ssize_t ivtvfb_write(struct fb_info *info, const char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long p = *ppos; + void *dst; + int err = 0; + unsigned long total_size; + struct ivtv *itv = (struct ivtv *) info->par; + unsigned long dma_offset = + IVTV_DECODER_OFFSET + itv->osd_info->video_rbase; + unsigned long dma_size; + u16 lead = 0, tail = 0; + + if (info->state != FBINFO_STATE_RUNNING) + return -EPERM; + + total_size = info->screen_size; + + if (total_size == 0) + total_size = info->fix.smem_len; + + if (p > total_size) + return -EFBIG; + + if (count > total_size) { + err = -EFBIG; + count = total_size; + } + + if (count + p > total_size) { + if (!err) + err = -ENOSPC; + + count = total_size - p; + } + + dst = (void __force *) (info->screen_base + p); + + if (info->fbops->fb_sync) + info->fbops->fb_sync(info); + + if (!access_ok(VERIFY_READ, buf, count)) { + IVTVFB_WARN("Invalid userspace pointer 0x%08lx\n", + (unsigned long)buf); + err = -EFAULT; + } + + if (!err) { + /* If transfer size > threshold and both src/dst + addresses are aligned, use DMA */ + if (count >= 4096 && ((u32)buf & 3) == ((u32)dst & 3)) { + /* Odd address = can't DMA. Align */ + if ((u32)dst & 3) { + lead = 4 - ((u32)dst & 3); + memcpy(dst, buf, lead); + buf += lead; + dst += lead; + } + /* DMA resolution is 32 bits */ + if ((count - lead) & 3) + tail = (count - lead) & 3; + /* DMA the data */ + dma_size = count - lead - tail; + err = ivtvfb_prep_dec_dma_to_device(itv, + p + lead + dma_offset, (void *)buf, dma_size); + dst += dma_size; + buf += dma_size; + /* Copy any leftover data */ + if (tail) + memcpy(dst, buf, tail); + } else { + memcpy(dst, buf, count); + } + } + + if (!err) + *ppos += count; + + return (err) ? err : count; +} + static int ivtvfb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg) { DEFINE_WAIT(wait); @@ -824,6 +905,7 @@ static int ivtvfb_blank(int blank_mode, struct fb_info *info) static struct fb_ops ivtvfb_ops = { .owner = THIS_MODULE, + .fb_write = ivtvfb_write, .fb_check_var = ivtvfb_check_var, .fb_set_par = ivtvfb_set_par, .fb_setcolreg = ivtvfb_setcolreg, |