From patchwork Wed Mar 20 07:39:25 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: 781499 Received: from cae.in-ulm.de (cae.in-ulm.de [217.10.14.231]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2FFBE224D7; Wed, 20 Mar 2024 07:40:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.10.14.231 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710920421; cv=none; b=gPnePPvFbrpk2fw8ETIJlDGIR2ho5+A9dODmIsh5kI7u/TwyDclrxSR1vr3cLbmUdge8P1saaotVXXVQFqVJz1GavHFV6FR8kjdG+QUrl6XNZSt38FC4Nsd8dvME3YYBvitMmY/Qtw2XLvUfq/4/wMojXM1H4+xoPWfrbZS573E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710920421; c=relaxed/simple; bh=wdumJfdBUiAeynPQ+4UsuFQrroX9g3XBCSeJGri3dZI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=n+Tu3Z2nA8n4QtJwI8LTv/VdGRLau04L+R0txW0rD4IiTpyC6TwqOu7a6aH51snhcZ+Y7Kx9iXFZtX/u1oiF5qhbUPCmpJXM2lGizOGSZbc8N+RzP4B9GBbdKch3f/9lVLoJqsIQ4K9sxmk5yKiZyRpuj1TBZPAB12NW5yCN+54= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=c--e.de; spf=pass smtp.mailfrom=c--e.de; arc=none smtp.client-ip=217.10.14.231 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 4F2C214092E; Wed, 20 Mar 2024 08:40:15 +0100 (CET) From: "Christian A. Ehrhardt" To: linux-kernel@vger.kernel.org Cc: "Christian A. Ehrhardt" , Heikki Krogerus , Greg Kroah-Hartman , Prashant Malani , Jameson Thies , Abhishek Pandit-Subedi , Neil Armstrong , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , =?utf-8?q?Samuel_=C4=8Cavoj?= , linux-usb@vger.kernel.org, Kenneth Crudup Subject: [PATCH 4/5] usb: typec: ucsi_acpi: Refactor and fix DELL quirk Date: Wed, 20 Mar 2024 08:39:25 +0100 Message-Id: <20240320073927.1641788-5-lk@c--e.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240320073927.1641788-1-lk@c--e.de> References: <20240320073927.1641788-1-lk@c--e.de> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Some DELL systems don't like UCSI_ACK_CC_CI commands with the UCSI_ACK_CONNECTOR_CHANGE but not the UCSI_ACK_COMMAND_COMPLETE bit set. The current quirk still leaves room for races because it requires two consecutive ACK commands to be sent. Refactor and significantly simplify the quirk to fix this: Send a dummy command and bundle the connector change ack with the command completion ack in a single UCSI_ACK_CC_CI command. This removes the need to probe for the quirk. While there define flag bits for struct ucsi_acpi->flags in ucsi_acpi.c and don't re-use definitions from ucsi.h for struct ucsi->flags. Fixes: f3be347ea42d ("usb: ucsi_acpi: Quirk to ack a connector change ack cmd") Cc: stable@vger.kernel.org Signed-off-by: Christian A. Ehrhardt Reviewed-by: Heikki Krogerus --- drivers/usb/typec/ucsi/ucsi_acpi.c | 75 +++++++++++++----------------- 1 file changed, 33 insertions(+), 42 deletions(-) diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c index 928eacbeb21a..7b3ac133ef86 100644 --- a/drivers/usb/typec/ucsi/ucsi_acpi.c +++ b/drivers/usb/typec/ucsi/ucsi_acpi.c @@ -23,10 +23,11 @@ struct ucsi_acpi { void *base; struct completion complete; unsigned long flags; +#define UCSI_ACPI_SUPPRESS_EVENT 0 +#define UCSI_ACPI_COMMAND_PENDING 1 +#define UCSI_ACPI_ACK_PENDING 2 guid_t guid; u64 cmd; - bool dell_quirk_probed; - bool dell_quirk_active; }; static int ucsi_acpi_dsm(struct ucsi_acpi *ua, int func) @@ -79,9 +80,9 @@ static int ucsi_acpi_sync_write(struct ucsi *ucsi, unsigned int offset, int ret; if (ack) - set_bit(ACK_PENDING, &ua->flags); + set_bit(UCSI_ACPI_ACK_PENDING, &ua->flags); else - set_bit(COMMAND_PENDING, &ua->flags); + set_bit(UCSI_ACPI_COMMAND_PENDING, &ua->flags); ret = ucsi_acpi_async_write(ucsi, offset, val, val_len); if (ret) @@ -92,9 +93,9 @@ static int ucsi_acpi_sync_write(struct ucsi *ucsi, unsigned int offset, out_clear_bit: if (ack) - clear_bit(ACK_PENDING, &ua->flags); + clear_bit(UCSI_ACPI_ACK_PENDING, &ua->flags); else - clear_bit(COMMAND_PENDING, &ua->flags); + clear_bit(UCSI_ACPI_COMMAND_PENDING, &ua->flags); return ret; } @@ -129,51 +130,40 @@ static const struct ucsi_operations ucsi_zenbook_ops = { }; /* - * Some Dell laptops expect that an ACK command with the - * UCSI_ACK_CONNECTOR_CHANGE bit set is followed by a (separate) - * ACK command that only has the UCSI_ACK_COMMAND_COMPLETE bit set. - * If this is not done events are not delivered to OSPM and - * subsequent commands will timeout. + * Some Dell laptops don't like ACK commands with the + * UCSI_ACK_CONNECTOR_CHANGE but not the UCSI_ACK_COMMAND_COMPLETE + * bit set. To work around this send a dummy command and bundle the + * UCSI_ACK_CONNECTOR_CHANGE with the UCSI_ACK_COMMAND_COMPLETE + * for the dummy command. */ static int ucsi_dell_sync_write(struct ucsi *ucsi, unsigned int offset, const void *val, size_t val_len) { struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi); - u64 cmd = *(u64 *)val, ack = 0; + u64 cmd = *(u64 *)val; + u64 dummycmd = UCSI_GET_CAPABILITY; int ret; - if (UCSI_COMMAND(cmd) == UCSI_ACK_CC_CI && - cmd & UCSI_ACK_CONNECTOR_CHANGE) - ack = UCSI_ACK_CC_CI | UCSI_ACK_COMMAND_COMPLETE; - - ret = ucsi_acpi_sync_write(ucsi, offset, val, val_len); - if (ret != 0) - return ret; - if (ack == 0) - return ret; - - if (!ua->dell_quirk_probed) { - ua->dell_quirk_probed = true; - - cmd = UCSI_GET_CAPABILITY; - ret = ucsi_acpi_sync_write(ucsi, UCSI_CONTROL, &cmd, - sizeof(cmd)); - if (ret == 0) - return ucsi_acpi_sync_write(ucsi, UCSI_CONTROL, - &ack, sizeof(ack)); - if (ret != -ETIMEDOUT) + if (cmd == (UCSI_ACK_CC_CI | UCSI_ACK_CONNECTOR_CHANGE)) { + cmd |= UCSI_ACK_COMMAND_COMPLETE; + + /* + * The UCSI core thinks it is sending a connector change ack + * and will accept new connector change events. We don't want + * this to happen for the dummy command as its response will + * still report the very event that the core is trying to clear. + */ + set_bit(UCSI_ACPI_SUPPRESS_EVENT, &ua->flags); + ret = ucsi_acpi_sync_write(ucsi, UCSI_CONTROL, &dummycmd, + sizeof(dummycmd)); + clear_bit(UCSI_ACPI_SUPPRESS_EVENT, &ua->flags); + + if (ret < 0) return ret; - - ua->dell_quirk_active = true; - dev_err(ua->dev, "Firmware bug: Additional ACK required after ACKing a connector change.\n"); - dev_err(ua->dev, "Firmware bug: Enabling workaround\n"); } - if (!ua->dell_quirk_active) - return ret; - - return ucsi_acpi_sync_write(ucsi, UCSI_CONTROL, &ack, sizeof(ack)); + return ucsi_acpi_sync_write(ucsi, UCSI_CONTROL, &cmd, sizeof(cmd)); } static const struct ucsi_operations ucsi_dell_ops = { @@ -209,13 +199,14 @@ static void ucsi_acpi_notify(acpi_handle handle, u32 event, void *data) if (ret) return; - if (UCSI_CCI_CONNECTOR(cci)) + if (UCSI_CCI_CONNECTOR(cci) && + !test_bit(UCSI_ACPI_SUPPRESS_EVENT, &ua->flags)) ucsi_connector_change(ua->ucsi, UCSI_CCI_CONNECTOR(cci)); if (cci & UCSI_CCI_ACK_COMPLETE && test_bit(ACK_PENDING, &ua->flags)) complete(&ua->complete); if (cci & UCSI_CCI_COMMAND_COMPLETE && - test_bit(COMMAND_PENDING, &ua->flags)) + test_bit(UCSI_ACPI_COMMAND_PENDING, &ua->flags)) complete(&ua->complete); }