/* --- Main FDC dispatcher --- */
static void fdc_execute(FDC_765 *self)
{
/* This code to dump out FDC commands as they are received is very useful
* in debugging
*
* */
int NC;
fdc_dprintf(5, "FDC: ");
for (NC = 0; NC < bytes_in_cmd[self->fdc_cmd_buf[0] & 0x1F]; NC++)
fdc_dprintf(5, "%02x ", self->fdc_cmd_buf[NC]);
fdc_dprintf(5, "\n");
/* */
/* Check if the DOR (ugh!) is being used to force us to a
different drive. */
fdc_dorcheck(self);
/* Reset "seek finished" flag */
self->fdc_st0 &= 0xBF;
switch(self->fdc_cmd_buf[0] & 0x1F)
{
case 2: fdc_read_track(self); break; /* 2: READ TRACK */
case 3: fdc_specify(self); break; /* 3: SPECIFY */
case 4: fdc_sense_drive(self); break; /* 4: SENSE DRV STATUS*/
case 5: fdc_write(self, 0); break; /* 5: WRITE */
case 6: fdc_read(self, 0); break; /* 6: READ */
case 7: fdc_recalibrate(self); break; /* 7: RECALIBRATE */
case 8: fdc_sense_int(self); break; /* 8: SENSE INT STATUS*/
case 9: fdc_write(self, 1); break; /* 9: WRITE DELETED */
case 10:fdc_read_id(self); break; /*10: READ ID */
case 12:fdc_read(self, 1); break; /*12: READ DELETED */
case 13:fdc_format(self); break; /*13: FORMAT TRACK */
case 15:fdc_seek(self); break; /*15: SEEK */
case 17: /*17: SCAN EQUAL */
case 25: /*25: SCAN LOW/EQUAL */
case 30:fdc_scan(self); break; /*30: SCAN HIGH/EQUAL*/
default:
fdc_dprintf(2, "Unknown FDC command %d\n",
self->fdc_cmd_buf[0] & 0x1F);
fdc_error(self); break;
}
}
/* Output a cmd_len long command string to the FDC.
* The FDC should be ready to receive a new command or
* an error (EBUSY or ETIME) will occur.
*/
int fdc_command(const __u8 * cmd_data, int cmd_len)
{
int result = 0;
unsigned long flags;
int count = cmd_len;
int retry = 0;
#ifdef TESTING
static unsigned int last_time;
unsigned int time;
#endif
TRACE_FUN(ft_t_any);
fdc_usec_wait(FT_RQM_DELAY); /* wait for valid RQM status */
spin_lock_irqsave(&fdc_io_lock, flags);
if (!in_interrupt())
/* Yes, I know, too much comments inside this function
* ...
*
* Yet another bug in the original driver. All that
* havoc is caused by the fact that the isr() sends
* itself a command to the floppy tape driver (pause,
* micro step pause). Now, the problem is that
* commands are transmitted via the fdc_seek
* command. But: the fdc performs seeks in the
* background i.e. it doesn't signal busy while
* sending the step pulses to the drive. Therefore the
* non-interrupt level driver has no chance to tell
* whether the isr() just has issued a seek. Therefore
* we HAVE TO have a look at the ft_hide_interrupt
* flag: it signals the non-interrupt level part of
* the driver that it has to wait for the fdc until it
* has completet seeking.
*
* THIS WAS PRESUMABLY THE REASON FOR ALL THAT
* "fdc_read timeout" errors, I HOPE :-)
*/
if (ft_hide_interrupt) {
restore_flags(flags);
TRACE(ft_t_info,
"Waiting for the isr() completing fdc_seek()");
if (fdc_interrupt_wait(2 * FT_SECOND) < 0) {
TRACE(ft_t_warn,
"Warning: timeout waiting for isr() seek to complete");
}
if (ft_hide_interrupt || !ft_seek_completed) {
/* There cannot be another
* interrupt. The isr() only stops
* the tape and the next interrupt
* won't come until we have send our
* command to the drive.
*/
TRACE_ABORT(-EIO, ft_t_bug,
"BUG? isr() is still seeking?\n"
KERN_INFO "hide: %d\n"
KERN_INFO "seek: %d",
ft_hide_interrupt,
ft_seek_completed);
}
fdc_usec_wait(FT_RQM_DELAY); /* wait for valid RQM status */
spin_lock_irqsave(&fdc_io_lock, flags);
}
fdc_status = inb(fdc.msr);
if ((fdc_status & FDC_DATA_READY_MASK) != FDC_DATA_IN_READY) {
spin_unlock_irqrestore(&fdc_io_lock, flags);
TRACE_ABORT(-EBUSY, ft_t_err, "fdc not ready");
}
fdc_mode = *cmd_data; /* used by isr */
#ifdef TESTING
if (fdc_mode == FDC_SEEK) {
time = ftape_timediff(last_time, ftape_timestamp());
if (time < 6000) {
TRACE(ft_t_bug,"Warning: short timeout between seek commands: %d",
time);
}
}
#endif
if (!in_interrupt()) {
/* shouldn't be cleared if called from isr
*/
ft_interrupt_seen = 0;
}
while (count) {
result = fdc_write(*cmd_data);
if (result < 0) {
TRACE(ft_t_fdc_dma,
"fdc_mode = %02x, status = %02x at index %d",
(int) fdc_mode, (int) fdc_status,
cmd_len - count);
if (++retry <= 3) {
TRACE(ft_t_warn, "fdc_write timeout, retry");
} else {
TRACE(ft_t_err, "fdc_write timeout, fatal");
/* recover ??? */
break;
}
} else {
--count;
++cmd_data;
}
}
#ifdef TESTING
if (fdc_mode == FDC_SEEK) {
last_time = ftape_timestamp();
}
#endif
spin_unlock_irqrestore(&fdc_io_lock, flags);
TRACE_EXIT result;
}
