[PATCH 5/9] macintosh/via-macii: Handle poll replies correctly

Finn Thain
2020-06-28T04:32:20Z

Userspace applications may use /dev/adb to send Talk requests. Such
requests always have req->reply_expected == 1. The same is true of Talk
requests sent by the kernel, except for poll requests queued internally
by the via-macii driver. Those requests have req->reply_expected == 0.

Consequently, poll reply packets get treated like autopoll reply packets.
(It doesn't make sense to try to distinguish them.) Always enter 'reading'
state after a poll request, so that the reply gets collected and passed
to adb_input(), and none go missing.

All Talk replies passed to adb_input() come from polling or autopolling,
so call adb_input() with the autopoll parameter set to 1.

Fixes: d95fd5fce88f0 ("m68k: Mac II ADB fixes") # v5.0+
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
---
drivers/macintosh/via-macii.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/macintosh/via-macii.c b/drivers/macintosh/via-macii.c
index d29c87943ca46..8d5ef77b4a435 100644
--- a/drivers/macintosh/via-macii.c
+++ b/drivers/macintosh/via-macii.c
@@ -463,6 +463,21 @@ static irqreturn_t macii_interrupt(int irq, void *arg)

via[ACR] &= ~SR_OUT;
x = via[SR];
+ } else if ((req->data[1] & OP_MASK) == TALK) {
+ macii_state = reading;
+
+ reading_reply = 0;
+ reply_ptr = reply_buf;
+ *reply_ptr = req->data[1];
+ reply_len = 1;
+
+ via[ACR] &= ~SR_OUT;
+ x = via[SR];
+
+ req->complete = 1;
+ current_req = req->next;
+ if (req->done)
+ (*req->done)(req);
} else {
macii_state = idle;

@@ -510,8 +525,9 @@ static irqreturn_t macii_interrupt(int irq, void *arg)
current_req = req->next;
if (req->done)
(*req->done)(req);
- } else if (reply_len && autopoll_devs) {
- adb_input(reply_buf, reply_len, 0);
+ } else if (reply_len && autopoll_devs &&
+ reply_buf[0] == last_poll_cmd) {
+ adb_input(reply_buf, reply_len, 1);
}
break;
}
--
2.26.2