From patchwork Wed Aug 18 12:16:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= X-Patchwork-Id: 12444285 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54302C4338F for ; Wed, 18 Aug 2021 12:17:29 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 10BE161029 for ; Wed, 18 Aug 2021 12:17:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 10BE161029 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=invisiblethingslab.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.168237.307155 (Exim 4.92) (envelope-from ) id 1mGKVH-0004Gm-QP; Wed, 18 Aug 2021 12:17:07 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 168237.307155; Wed, 18 Aug 2021 12:17:07 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mGKVH-0004Gf-NS; Wed, 18 Aug 2021 12:17:07 +0000 Received: by outflank-mailman (input) for mailman id 168237; Wed, 18 Aug 2021 12:17:07 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mGKVG-0004GZ-Sh for xen-devel@lists.xenproject.org; Wed, 18 Aug 2021 12:17:07 +0000 Received: from out1-smtp.messagingengine.com (unknown [66.111.4.25]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 32b54d3e-001e-11ec-a549-12813bfff9fa; Wed, 18 Aug 2021 12:17:05 +0000 (UTC) Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id C09645C013E; Wed, 18 Aug 2021 08:17:05 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute4.internal (MEProxy); Wed, 18 Aug 2021 08:17:05 -0400 Received: by mail.messagingengine.com (Postfix) with ESMTPA; Wed, 18 Aug 2021 08:17:03 -0400 (EDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 32b54d3e-001e-11ec-a549-12813bfff9fa DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=WK7aJH zAWiHIDyinLYF6llZgglqbrKg3e8i20rp8HeU=; b=JqNwioQhZiIfRm+iKofegt pvnDCtMnurud/eEDk1AmpEwefySfLfsA3hrE2jCVuUa1aJoqH6lByfmO1oSlrbCW +XEU86568DOu2uAZ884juO6g1ngI2kNuWAKD55sm5I1wyZ50jTm9mb171dnW1cVj F03rDe+ZLQqNPTj4xuTXvBEoNWt6mTpW/g+wAlkOa+96AaiprfvTy+FBYvClcAcK 7Y+E6tMj1drAQ1JH+CkzcHexdU+fNBEJVgmYzARBRQxyQ1BA4ddVt9ZdKeJh5Tbx 5zzU8HTGaLeEulfl0xaYVLDWT6sisrcIVYW4RRNfV1BV1Z2CHZPYa1dLO27kGwDQ == X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvtddrleehgdehtdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkofggtghogfesthekredtredtjeenucfhrhhomhepofgrrhgvkhcu ofgrrhgtiiihkhhofihskhhiqdfikphrvggtkhhiuceomhgrrhhmrghrvghksehinhhvih hsihgslhgvthhhihhnghhslhgrsgdrtghomheqnecuggftrfgrthhtvghrnhepteegteek ueekfffhjeeuleduheettdekueeitdfggfdthfevfeeuieeihfduheegnecuvehluhhsth gvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepmhgrrhhmrghrvghksehi nhhvihhsihgslhgvthhhihhnghhslhgrsgdrtghomh X-ME-Proxy: From: =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= To: xen-devel@lists.xenproject.org Cc: =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= , Jan Beulich , Andrew Cooper , George Dunlap , Ian Jackson , Julien Grall , Stefano Stabellini , Wei Liu Subject: [PATCH v2 1/2] ns16550: do not override fifo size if explicitly set Date: Wed, 18 Aug 2021 14:16:47 +0200 Message-Id: <20210818121649.462413-1-marmarek@invisiblethingslab.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Organization: Invisible Things Lab If fifo size is already set via uart_params, do not force it to 16 - which may not match the actual hardware. Specifically Exar cards have fifo of 256 bytes. Signed-off-by: Marek Marczykowski-Górecki Reviewed-by: Jan Beulich --- xen/drivers/char/ns16550.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c index 16a73d0c0e47..97b85b0225cc 100644 --- a/xen/drivers/char/ns16550.c +++ b/xen/drivers/char/ns16550.c @@ -357,7 +357,8 @@ static void __init ns16550_init_preirq(struct serial_port *port) ns16550_setup_preirq(uart); /* Check this really is a 16550+. Otherwise we have no FIFOs. */ - if ( ((ns_read_reg(uart, UART_IIR) & 0xc0) == 0xc0) && + if ( uart->fifo_size <= 1 && + ((ns_read_reg(uart, UART_IIR) & 0xc0) == 0xc0) && ((ns_read_reg(uart, UART_FCR) & UART_FCR_TRG14) == UART_FCR_TRG14) ) uart->fifo_size = 16; }