Commit 624cf5b5 authored Jun 28, 2020 by Finn Thain Committed by Michael Ellerman Jul 26, 2020

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: d95fd5fc ("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

parent b16b6768

drivers/macintosh/via-macii.c

+18 −2

Original line number	Diff line number	Diff line
		@@ -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;
		}