Klaus Schmidinger wrote: > VDR User wrote: > > On 1/31/07, *Klaus Schmidinger* <Klaus.Schmidinger@xxxxxxxxxx > > <mailto:Klaus.Schmidinger@xxxxxxxxxx>> wrote: > > > > VDR User wrote: > > > From what he's saying, the problem is buffer overrun's, not > > underrun's. Afaics this is just a guess. We need a sample recording and track down what happens in the driver/firmware. > > > Too much data is being sent and the device isn't able to keep up. If > > > that's the case then it would make sense for vdr to have a user > > setting > > > to limit how many seconds (or milliseconds perhaps?) worth of data is > > > sent to the buffer. I can't think of any reason not to add such a > > > feature if it means better usability for the end-user. > > > > If the device can't take any more data, it should just refuse to > > accept it and return from the write() call without anything written. Code from the driver: | ... | if (nonblock && !FREE_COND) | return -EWOULDBLOCK; | | while (todo > 0) { | if (!FREE_COND) { | if (nonblock) | return count - todo; | if (wait_event_interruptible(av7110->avout.queue, | FREE_COND)) | return count - todo; | } | ... Looks ok to me. The driver does not accept more data than it can handle. > > I disagree. Simply returning from write() implies the data was written > > and the device is ready for more. > > The write() function returns the number of bytes actually written, > which is not necessarily the same as the number of bytes the caller > wanted to write. So the device can chose not to accept all of the data. > If the device is currently unable to accept any data (and the file handle > is in O_NONBLOCK mode) it shall return EAGAIN to inform the caller that > it is currently busy and that the caller should try again later. > > > If this is not true then you risk > > making the sync even worse. I consulted with people familiar with this > > type of stuff and it was suggested the problem could (and should) be > > fixed at the driver level so I'm following up on that now. > > Well, that's exactly what I was suggesting. The write() function has > everything it takes to block data from coming into the device if its > buffer is full. No need for the caller to do any funny estimates here. Fullack. There is no reason to add workarounds like this to VDR. @all: Don't panic. Provide samples. :-) Oliver -- -------------------------------------------------------- VDR Remote Plugin 0.3.9 available at http://www.escape-edv.de/endriss/vdr/ --------------------------------------------------------
