diff options
Diffstat (limited to 'sys/dev/fdc/fdcreg.h')
-rw-r--r-- | sys/dev/fdc/fdcreg.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/sys/dev/fdc/fdcreg.h b/sys/dev/fdc/fdcreg.h index c082668..893aefd 100644 --- a/sys/dev/fdc/fdcreg.h +++ b/sys/dev/fdc/fdcreg.h @@ -69,3 +69,15 @@ #define FDI_DCHG 0x80 /* diskette has been changed */ /* requires drive and motor being selected */ /* is cleared by any step pulse to drive */ + +/* + * Timeout value for the PIO loops to wait until the FDC main status + * register matches our expextations (request for master, direction + * bit). This is the number of cycles to loop while waiting, with a + * 1-microsecond (in theory) DELAY() in each cycle. In particular on + * slower hardware, it could take a fair amount more to execute. Of + * course, as soon as the FDC main status register indicates the correct + * bits are set, the loop will terminate, so this is merely a safety + * measure to avoid looping forever in case of broken hardware. + */ +#define FDSTS_TIMEOUT 200 |