I wrote:
Since FFADO applies 200 ms or more as FCP transaction timeout, shouldn't firewire-lib's fcp.c increase FCP_TIMEOUT_MS from 125 to 200 or more as well?
FFADO took over the 200 ms timeout from libavc1394, where it was introduced by this changeset: http://sourceforge.net/p/libavc1394/code/24/
Commit [r24] increase timeout Authored by: ddennedy 2002-10-01
--- a/trunk/libavc1394/libavc1394/avc1394_internal.h +++ b/trunk/libavc1394/libavc1394/avc1394_internal.h @@ -8,7 +8,7 @@ #define MAX_RESPONSE_SIZE 512 #define AVC1394_RETRY 2 #define AVC1394_SLEEP 10000 -#define AVC1394_POLL_TIMEOUT 100 +#define AVC1394_POLL_TIMEOUT 200 /* #define DEBUG */
void htonl_block(quadlet_t *buf, int len);
So this was certainly not done particularly for audio devices. And interestingly, the immediate parent commit r23 on 2002-09-28 corrected the timeout from 50 ms to 100 ms.