On Sat, 2018-02-03 at 15:17 -0500, Kevin O'Connor wrote:
On Sat, Feb 03, 2018 at 07:46:11PM +0200, Nikolay Nikolov wrote:
The problem with using floppy_motor_counter was that, after it reaches 0, it immediately stops the floppy motors, which is not what is supposed to happen on real hardware. Instead, after a timeout (like in the end of every floppy operation, regardless of the result - success, timeout or error), the floppy motors must be kept spinning for additional 2 seconds (the FLOPPY_MOTOR_TICKS). So, now the floppy_motor_counter is initialized to 255 (the max value) in the beginning of the floppy operation (in floppy_turn_on_motor()). For IRQ timeouts, a different timeout is used, specified by the new FLOPPY_IRQ_TIMEOUT constant (currently set to 5 seconds - a fairly conservative value, but should work reliably on most floppies).
After the floppy operation, floppy_turn_off_motor_delayed() resets the floppy_motor_counter to 2 seconds (FLOPPY_MOTOR_TICKS).
This is also consistent with what other PC BIOSes do.
Signed-off-by: Nikolay Nikolov nickysn@users.sourceforge.net
src/hw/floppy.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/src/hw/floppy.c b/src/hw/floppy.c index acaff3f..6714402 100644 --- a/src/hw/floppy.c +++ b/src/hw/floppy.c @@ -34,6 +34,7 @@ #define FLOPPY_GAPLEN 0x1B #define FLOPPY_FORMAT_GAPLEN 0x6c #define FLOPPY_PIO_TIMEOUT 1000 +#define FLOPPY_IRQ_TIMEOUT 5000
#define FLOPPY_DOR_MOTOR_D 0x80 // Set to turn drive 3's motor ON #define FLOPPY_DOR_MOTOR_C 0x40 // Set to turn drive 2's motor ON @@ -221,8 +222,9 @@ floppy_wait_irq(void) { u8 frs = GET_BDA(floppy_recalibration_status); SET_BDA(floppy_recalibration_status, frs & ~FRS_IRQ);
- u32 end = timer_calc(FLOPPY_IRQ_TIMEOUT); for (;;) {
if (!GET_BDA(floppy_motor_counter)) {
if (timer_check(end)) { warn_timeout(); floppy_disable_controller(); return DISK_RET_ETIMEOUT;Thanks. This patch looks good to me.
One question - if floppy_wait_irq() no longer accesses floppy_motor_counter, can we also change floppy_enable_controller() to not alter floppy_motor_counter as well? That is, can we treat floppy_motor_counter as part of the logic to send commands to drives (as opposed to sending commands to the controller) and thus limit floppy_motor_counter logic to the floppy_drive_pio() code?
Yes, I think so. Should I amend it to this patch?
-Kevin