From bbe2486fe3bd6c7cffaf4123b7e86a55c209ed44 Mon Sep 17 00:00:00 2001 From: Trent Piepho Date: Fri, 27 Apr 2007 22:56:29 -0300 Subject: [PATCH] V4L/DVB (5571): V4l1-compat: Make VIDIOCSPICT return errors in a useful way Among other things, VIDIOCSPICT sets the pixel format. Some drivers don't support all formats, e.g. cx88 doesn't support the planar formats. The compat code that translates VIDIOCSPICT into V4L2 ioctls doesn't pass on any errors, so a userspace program doesn't know if it has selected an unsupported pixel format. VIDIOCSPICT sets both the memory capture and overlay formats, and it's possible that one will be set while the other will fail, e.g. cx88 doesn't even support overlay. Also, trying to set the overlay format will fail for non-root users. Signed-off-by: Trent Piepho Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/v4l1-compat.c | 54 +++++++++++++++++++++++-------- 1 file changed, 41 insertions(+), 13 deletions(-) diff --git a/drivers/media/video/v4l1-compat.c b/drivers/media/video/v4l1-compat.c index efb67d29fc0..ede8543818b 100644 --- a/drivers/media/video/v4l1-compat.c +++ b/drivers/media/video/v4l1-compat.c @@ -616,6 +616,8 @@ v4l_compat_translate_ioctl(struct inode *inode, case VIDIOCSPICT: /* set tone controls & partial capture format */ { struct video_picture *pict = arg; + int mem_err = 0, ovl_err = 0; + memset(&fbuf2, 0, sizeof(fbuf2)); set_v4l_control(inode, file, @@ -628,33 +630,59 @@ v4l_compat_translate_ioctl(struct inode *inode, V4L2_CID_SATURATION, pict->colour, drv); set_v4l_control(inode, file, V4L2_CID_WHITENESS, pict->whiteness, drv); + /* + * V4L1 uses this ioctl to set both memory capture and overlay + * pixel format, while V4L2 has two different ioctls for this. + * Some cards may not support one or the other, and may support + * different pixel formats for memory vs overlay. + */ fmt2 = kzalloc(sizeof(*fmt2),GFP_KERNEL); fmt2->type = V4L2_BUF_TYPE_VIDEO_CAPTURE; err = drv(inode, file, VIDIOC_G_FMT, fmt2); - if (err < 0) + /* If VIDIOC_G_FMT failed, then the driver likely doesn't + support memory capture. Trying to set the memory capture + parameters would be pointless. */ + if (err < 0) { dprintk("VIDIOCSPICT / VIDIOC_G_FMT: %d\n",err); - if (fmt2->fmt.pix.pixelformat != - palette_to_pixelformat(pict->palette)) { + mem_err = -1000; /* didn't even try */ + } else if (fmt2->fmt.pix.pixelformat != + palette_to_pixelformat(pict->palette)) { fmt2->fmt.pix.pixelformat = palette_to_pixelformat( pict->palette); - err = drv(inode, file, VIDIOC_S_FMT, fmt2); - if (err < 0) - dprintk("VIDIOCSPICT / VIDIOC_S_FMT: %d\n",err); + mem_err = drv(inode, file, VIDIOC_S_FMT, fmt2); + if (mem_err < 0) + dprintk("VIDIOCSPICT / VIDIOC_S_FMT: %d\n", + mem_err); } err = drv(inode, file, VIDIOC_G_FBUF, &fbuf2); - if (err < 0) + /* If VIDIOC_G_FBUF failed, then the driver likely doesn't + support overlay. Trying to set the overlay parameters + would be quite pointless. */ + if (err < 0) { dprintk("VIDIOCSPICT / VIDIOC_G_FBUF: %d\n",err); - if (fbuf2.fmt.pixelformat != - palette_to_pixelformat(pict->palette)) { + ovl_err = -1000; /* didn't even try */ + } else if (fbuf2.fmt.pixelformat != + palette_to_pixelformat(pict->palette)) { fbuf2.fmt.pixelformat = palette_to_pixelformat( pict->palette); - err = drv(inode, file, VIDIOC_S_FBUF, &fbuf2); - if (err < 0) - dprintk("VIDIOCSPICT / VIDIOC_S_FBUF: %d\n",err); - err = 0; /* likely fails for non-root */ + ovl_err = drv(inode, file, VIDIOC_S_FBUF, &fbuf2); + if (ovl_err < 0) + dprintk("VIDIOCSPICT / VIDIOC_S_FBUF: %d\n", + ovl_err); } + if (ovl_err < 0 && mem_err < 0) + /* ioctl failed, couldn't set either parameter */ + if (mem_err != -1000) { + err = mem_err; + } else if (ovl_err == -EPERM) { + err = 0; + } else { + err = ovl_err; + } + else + err = 0; break; } case VIDIOCGTUNER: /* get tuner information */ -- 2.41.0