On Sun, 4 Mar 2018, I wrote:
> > + } else {
> > + scsi_esp_cmd(esp, ESP_CMD_FLUSH);
> > +
> > + if (esp_count >= ZORRO_ESP_FIFO_SIZE) {
> > + ZORRO_ESP_PIO_FILL("%0@+,%2@", esp_count);
> > + } else {
> > + ZORRO_ESP_PIO_LOOP("%0@+,%2@", esp_count);
> > + }
> > +
> > + scsi_esp_cmd(esp, cmd);
> > +
> > + while (esp_count) {
> > + unsigned int n;
> > +
> > + if (zorro_esp_wait_for_intr(esp))
> > + break;
> > +
> > + if ((esp->sreg & ESP_STAT_PMASK) != phase)
> > + break;
> > +
> > + esp->ireg = zorro_esp_read8(esp, ESP_INTRPT);
> > + /* This is tricky - ~ESP_INTR_BSERV is the wrong mask
> > + * a ESP_CMD_SELAS command which also generates
> > + * ESP_INTR_FDONE! Use ~(ESP_INTR_BSERV|ESP_INTR_FDONE)
> > + * since ESP_INTR_FDONE is not raised by any other
> > + * error condition. Unfortunately, this is still not
> > + * sufficient to make the single message byte transfer
> > + * of ESP_CMD_SELAS work ...
> > + */
>
> Is that comment correct? This is the !write branch, that is, read
> acccess from memory. But tag bytes move in the other direction for
> ESP_CMD_SELAS.
>
Nevermind -- I got the direction wrong there.
But if your comment is correct and the mask is wrong, that problem should
show up in mac_esp too, right?
The whole TCQ problem showed up, and was fixed by checking ESP_INTR_FDONE
in the Message In transfer.
> > + if (esp->ireg & ~(ESP_INTR_BSERV | ESP_INTR_FDONE)) {
> > + zep->error = 1;
> > + break;
> > + }
If you really do get ESP_INTR_FDONE instead of ESP_INTR_BSERV for Message
Out, wouldn't it be safer (and more consistent) to do,
if (esp->ireg & mask) {
mep->error = 1;
break;
}
and initialize mask as,
u8 mask = ~(phase == ESP_MIP || phase == ESP_MOP ? ESP_INTR_FDONE
: ESP_INTR_BSERV);
to cover both !write and write?
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