From patchwork Wed Jan 3 10:06:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Christian A. Ehrhardt" X-Patchwork-Id: 759815 Received: from cae.in-ulm.de (cae.in-ulm.de [217.10.14.231]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 42D5B18632; Wed, 3 Jan 2024 10:06:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=c--e.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=c--e.de Received: by cae.in-ulm.de (Postfix, from userid 1000) id 10E881408EB; Wed, 3 Jan 2024 11:06:50 +0100 (CET) From: "Christian A. Ehrhardt" To: linux-usb@vger.kernel.org Cc: "Christian A. Ehrhardt" , Heikki Krogerus , Greg Kroah-Hartman , Neil Armstrong , Hans de Goede , Mario Limonciello , Saranya Gopal , linux-kernel@vger.kernel.org Subject: [RFC] Fix stuck UCSI controller on DELL Date: Wed, 3 Jan 2024 11:06:35 +0100 Message-Id: <20240103100635.57099-1-lk@c--e.de> X-Mailer: git-send-email 2.30.2 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 I have a DELL Latitude 5431 where typec only works somewhat. After the first plug/unplug event the PPM seems to be stuck and commands end with a timeout (GET_CONNECTOR_STATUS failed (-110)). This patch fixes it for me but according to my reading it is in violation of the UCSI spec. On the other hand searching through the net it appears that many DELL models seem to have timeout problems with UCSI. Do we want some kind of quirk here? There does not seem to be a quirk framework for this part of the code, yet. Or is it ok to just send the additional ACK in all cases and hope that the PPM will do the right thing? regards Christian diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index 61b64558f96c..65098a454f63 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -53,7 +53,10 @@ static int ucsi_acknowledge_connector_change(struct ucsi *ucsi) ctrl = UCSI_ACK_CC_CI; ctrl |= UCSI_ACK_CONNECTOR_CHANGE; - return ucsi->ops->sync_write(ucsi, UCSI_CONTROL, &ctrl, sizeof(ctrl)); + if (ucsi->ops->sync_write(ucsi, UCSI_CONTROL, &ctrl, sizeof(ctrl))) + pr_err("ACK FAILED\n"); + + return ucsi_acknowledge_command(ucsi); } static int ucsi_exec_command(struct ucsi *ucsi, u64 command);