Hi Mark,
On 7/31/19 6:32 PM, Mark Balantzyan wrote:
Hi Hans, all,
Sorry for the poor patching, I am a student and as you may tell still
new to this system. At the time of the patching, I wasn't fully informed
of all the requirements that go into such things, and am still learning.
Would it be alright if I submit a report instead? In order to, I am
(still, sorry) trying to understand the issue at hand. How in fact may
the release() callback be overridden (by a tw686x-specific function) to
free the dma memory and call video_device_release()? To my understanding
at the time, this was merely a re-implementation of video_device_release
with said requirements and subtraction of extra features from
tw686x_video_free()..
Sorry, you'll need to discuss this with your mentor. I really don't have
time to look at reports or anything like that. I'm a media subsystem
maintainer, not your mentor. And I expect that you spend time trying to
understand the code by looking at how other drivers do this and look at
kernel documentation like this:
https://linuxtv.org/downloads/v4l-dvb-apis-new/media_kapi.html
Regards,
Hans
This release() callback is called by the V4L2 framework when the
last user
of the device closes its filehandle, so that's a good point to free
all
the memory. Doing it earlier (as the current code does) runs the
risk that someone might
still access that memory, and you don't want that.
Yes, I definitely don't want that. :)
Thank you,
Mark
