From patchwork Fri Nov 20 04:39:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Finn Thain X-Patchwork-Id: 1403478 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4CcklB0SLdz9sT6 for ; Fri, 20 Nov 2020 15:55:50 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=telegraphics.com.au Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4CcklB006xzDqws for ; Fri, 20 Nov 2020 15:55:49 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=telegraphics.com.au (client-ip=98.124.60.144; helo=kvm5.telegraphics.com.au; envelope-from=fthain@telegraphics.com.au; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=telegraphics.com.au Received: from kvm5.telegraphics.com.au (kvm5.telegraphics.com.au [98.124.60.144]) by lists.ozlabs.org (Postfix) with ESMTP id 4CckfM5jTqzDqw8 for ; Fri, 20 Nov 2020 15:51:39 +1100 (AEDT) Received: by kvm5.telegraphics.com.au (Postfix, from userid 502) id 508152A45D; Thu, 19 Nov 2020 23:51:37 -0500 (EST) To: Benjamin Herrenschmidt , Michael Ellerman Message-Id: <0f0a25855391e7eaa53a50f651aea0124e8525dd.1605847196.git.fthain@telegraphics.com.au> From: Finn Thain Subject: [PATCH] macintosh/adb-iop: Always wait for reply message from IOP Date: Fri, 20 Nov 2020 15:39:56 +1100 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Joshua Thompson Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" A recent patch incorrectly altered the adb-iop state machine behaviour and introduced a regression that can appear intermittently as a malfunctioning ADB input device. This seems to be caused when reply packets from different ADB commands become mixed up, especially during the adb bus scan. Fix this by unconditionally entering the awaiting_reply state after sending an explicit command, even when the ADB command won't generate a reply from the ADB device. Cc: Joshua Thompson Fixes: e2954e5f727f ("macintosh/adb-iop: Implement sending -> idle state transition") Tested-by: Stan Johnson Signed-off-by: Finn Thain --- drivers/macintosh/adb-iop.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/macintosh/adb-iop.c b/drivers/macintosh/adb-iop.c index 6b26b6a2c463..0ee327249150 100644 --- a/drivers/macintosh/adb-iop.c +++ b/drivers/macintosh/adb-iop.c @@ -84,10 +84,7 @@ static void adb_iop_complete(struct iop_msg *msg) local_irq_save(flags); - if (current_req->reply_expected) - adb_iop_state = awaiting_reply; - else - adb_iop_done(); + adb_iop_state = awaiting_reply; local_irq_restore(flags); } @@ -95,8 +92,9 @@ static void adb_iop_complete(struct iop_msg *msg) /* * Listen for ADB messages from the IOP. * - * This will be called when unsolicited messages (usually replies to TALK - * commands or autopoll packets) are received. + * This will be called when unsolicited IOP messages are received. + * These IOP messages can carry ADB autopoll responses and also occur + * after explicit ADB commands. */ static void adb_iop_listen(struct iop_msg *msg) @@ -123,8 +121,10 @@ static void adb_iop_listen(struct iop_msg *msg) if (adb_iop_state == awaiting_reply) { struct adb_request *req = current_req; - req->reply_len = amsg->count + 1; - memcpy(req->reply, &amsg->cmd, req->reply_len); + if (req->reply_expected) { + req->reply_len = amsg->count + 1; + memcpy(req->reply, &amsg->cmd, req->reply_len); + } req_done = true; }