Em 19-01-2011 09:59, Hans Verkuil escreveu: >> Em 19-01-2011 05:39, Hans Verkuil escreveu: >>> Hi Mauro, >>> >>> We want to rename video_device to v4l2_devnode. So let me know when I >>> can >>> finalize my patches and, most importantly, against which branch. >>> >>> My current tree: >>> >>> http://git.linuxtv.org/hverkuil/media_tree.git?a=shortlog;h=refs/heads/devnode2 >>> >>> tracks for_2.6.38-rc1 and should apply cleanly at the moment. >> >> Even not being able to handle it for .38, I did a look on the proposed >> changes. I'm not convinced about those renaming stuff. >> >> By looking on other subsystems, it seems to me that >> video_device_register() >> is a better name than any other name. Btw, by far, the use of _node for >> the >> device registration on Linux kernel is not usual at all: >> >> $ git grep -e "_register" --and -e "(" --and -e "node" include |grep -v >> "of_mdiobus_register(" >> include/linux/compaction.h:extern int compaction_register_node(struct node >> *node); >> include/linux/compaction.h:static inline int >> compaction_register_node(struct node *node) >> include/linux/swap.h:extern int scan_unevictable_register_node(struct node >> *node); >> include/linux/swap.h:static inline int >> scan_unevictable_register_node(struct node *node) >> >> There are only 2 functions using it. On those, the "node" at the function >> register name is due to "struct node", and they likely make sense. >> >> A seek for *register*device or *device*register patterns show a lot: >> >> $ git grep -e "_register_device" --and -e "(" include|wc -l >> 28 >> >> $ git grep -e "_device_register" --and -e "(" include|wc -l >> 32 >> >> Basically, what I'm trying to say is that, on all subsystems, the function >> that creates >> the devices is called *register*device or *device*register. >> >> Why should we adopt anything different than the kernel convention for >> V4L2? > > I'm sure we went through this before. Maybe. > 1) the name originates from the time that drivers had only one video node. > It makes little sense anymore when drivers can create many video, radio, > vbi and later v4l-subdev nodes. The key thing is that this driver > registers a V4L2 node. Each of those has its own struct device, so each of those are different devices. As we've discussed previously, "subdev" is a bad name, as, on Linux, everything that ultimately creates a /dev on userspace is a device. > 2) struct v4l2_device and struct video_device look too similar. While > v4l2_device represents the whole V4L2 hardware, the video_device > represents the video/radio/vbi/... device node only. So, maybe v4l2_device is not a good name for it, as it is a set of video devices. > 3) (less important) all types/functions within the v4l2 framework now have > the v4l2_ prefix, except this one. Aligning this will make everything more > consistent and recognizable. > > We're not like most other subsystems where often just a single device node > is registered. We have much more complex hardware. So I think that > 'v4l2_devnode' much more clearly identifies what it represents than > 'video_device'. There are other subsystems where drivers register several devices. For example, I have one 3G modem here that registers 4 devices. Cheers, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
