On Thu, 2011-03-17 at 15:08 -0400, Jarod Wilson wrote: > On Thu, Mar 17, 2011 at 12:16:31PM -0400, Andy Walls wrote: > > Jarod Wilson <jarod@xxxxxxxxxx> wrote: > . > > > > But the orignal intent of the check I put in was to avoid passing > partial/junk data to userspace, and go around again to see if good > data could be provided. > > > > Your check bails when good data that might be sitting there still. > That doesn't seem like a good trade for supporting backward compat for > old kernels. > > Ah. Another thing I neglected to notice then. :) > > Perhaps there should be a retry count check as well then, as otherwise, > its possible to get stuck in that loop forever (which is what was > happening on older kernels). Its conceivable that similar could happen on > a newer kernel for some reason. Well, lets see, >From the perspective of userspace & lircd: 1. A specification compliance failure for a corner case isn't too bad (bailing out on junk and leaving good data behind) 2. An unrecoverable failure for any case is very bad (spinning/hanging on a result that won't change) 3. Sending unitialized bytes out to userspace with copy_to_user() is very bad. (I recall the old code would do the copy to user and always tell userspace it got a code whether it read anything out of the buffer or not. IIRC, that leaked information off the stack.) If the code as patched avoids the two very bad things (#2 and #3), then the patch is OK by me. Regards, Andy -- 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
