macintosh/via-macii: Handle poll replies correctly

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+
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/754cddfa045e5bfa53e5da199831de02e7d2f27f.1593318192.git.fthain@telegraphics.com.au

diff --git a/drivers/macintosh/via-macii.c b/drivers/macintosh/via-macii.c
index d29c879..8d5ef77 100644 (file)
--- 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;
                        }