From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A1ACC606A31C for ; Mon, 9 Nov 2026 14:55:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=d0uNbttl; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=Fu0lbhZg DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: References:Message-ID:In-Reply-To:Subject:cc:To:Date:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=OPMTYrIv7U1UWYQ/ULbovNNC49g7R/EbhbaHljblfH8=; b=d0uNbttl29Hv9wXbkTSOCGZQIQ b478v75VTOYeo5sj6A38Tlqw7ah0lAZQNIOSyGXLpQRpLk9IY6ylaDfSRclP/H6zjilXWtzIh+Ci4 wHymWYO9yTmwnLfJpoJ0WA07y8K2I9dXlZXTkQiei66wOC5kjKg7F0x7jhDBSHZPN1kFXr1z+k16H UukYOaGjVLZT1Fa5jDVZ5WeelHlfmzUmBTY8VcHragIocfOUobs+p+sOUWApHJMCs80Fsd5WpiqgK QcMX1x2lw0VQjnWvig44UeFydzzUa47h/uFzQWWUGbLQQtcPLUr8l4ZFs8OHsdPVRFfoVvfyC4psQ ADk/32iA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xQQmc-00000000zi2-2Q3f; Mon, 09 Nov 2026 14:55:42 +0000 Received: from mgamail.intel.com ([198.175.65.13]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xQQmZ-00000000zh9-3Rq5; Mon, 09 Nov 2026 14:55:41 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1794236140; x=1825772140; h=from:date:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=rVCjiIFvC6E3quo9l3R3aM1S43mCGLdSCsEF+O0+dgI=; b=Fu0lbhZgErFZSYNw/jumzy+GMcGtVgBCmnERJ5MztOSZHy6dJVqjE1J8 v5jO/liCvzsUmIkEOD9ffNNOOwVt+9NLKvUi1gcNy6FvDQvFLbr9U8nze mdMildCk7k6vEaL6JfVcmjjLNQY+yRbo8eS1Kja0j1M+cvtn59GQlAZO2 pzw1Fh+hFEmRAgU51FdqF9+ZfOQeP2mnJ510zw5ZqjN7meZgrZ5wKiTKb aCYAWYfURHtjULoHIzB0HdEgude8C7pq5XqBLB0Lto3XVvFDz+7INWoOp ONjxXDDGZZ9j9P4rLfAo4ClF1yWveaHkmDTzZtqZnY5DicWWJh0ZCjJYH w==; X-CSE-ConnectionGUID: uF7wKgK3SEeneaNg+pySaQ== X-CSE-MsgGUID: WOKi1LV7TYO6wK0Hz387kw== X-IronPort-AV: E=McAfee;i="6800,10657,11961"; a="2838445" X-IronPort-AV: E=Sophos;i="6.27,204,1787036400"; d="scan'208";a="2838445" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Nov 2026 06:55:39 -0800 X-CSE-ConnectionGUID: 3vrj6c/cR9C6/ZvLjx0OWg== X-CSE-MsgGUID: CYuhuV9PRZqMOFS1UElLLQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,204,1787036400"; d="scan'208";a="8218137" Received: from ijarvine-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.244.139]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Nov 2026 06:55:35 -0800 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Mon, 9 Nov 2026 16:55:31 +0200 (EET) To: =?ISO-8859-2?Q?Kry=B9tof_=C8ern=FD?= cc: Andy Shevchenko , Greg Kroah-Hartman , Jiri Slaby , Heiko Stuebner , LKML , linux-serial , linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, Miroslav Ondra Subject: Re: [PATCH 1/2] serial: 8250: Add RX trigger levels for U6_16550A In-Reply-To: <20261109-8250-select-u6-64bit-v1-1-04bc8332fa34@gmail.com> Message-ID: <469362ef-f0c5-45f2-746a-b4a3c51876a4@linux.intel.com> References: <20261109-8250-select-u6-64bit-v1-0-04bc8332fa34@gmail.com> <20261109-8250-select-u6-64bit-v1-1-04bc8332fa34@gmail.com> X-Archived-By: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323328-656436369-1794236131=:1181" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261109_065539_902760_3612381D X-CRM114-Status: GOOD ( 18.47 ) X-Spam-Score: -4.2 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-13.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323328-656436369-1794236131=:1181 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE On Mon, 9 Nov 2026, Kry=C5=A1tof =C4=8Cern=C3=BD via B4 Relay wrote: > From: Kry=C5=A1tof =C4=8Cern=C3=BD >=20 > PORT_U6_16550A has a 64-byte FIFO but no rxtrig_bytes table, so the > rx_trig_bytes sysfs attribute is not registered for ports of this type > and the RX trigger level cannot be read or changed from userspace. >=20 > Add a table with 1, 16, 32 and 62 bytes, i.e. 1 character, FIFO 1/4 > full, FIFO 1/2 full and FIFO 2 less than full. These are the levels the > Synopsys DesignWare UART uses for a 64-byte FIFO, and they match the > existing PORT_ALTR_16550_F64 table. >=20 > The default FCR value of the type is unchanged, so the trigger level a > port starts with stays at 1/2 full. The only visible change for ports > already detected as U6_16550A by autoconfig is the new sysfs attribute. >=20 > This prepares for 8250_dw selecting PORT_U6_16550A for DesignWare UARTs > with a 64-byte FIFO. >=20 > Co-developed-by: Miroslav Ondra > Signed-off-by: Miroslav Ondra > Signed-off-by: Kry=C5=A1tof =C4=8Cern=C3=BD > --- > drivers/tty/serial/8250/8250_port.c | 1 + > 1 file changed, 1 insertion(+) >=20 > diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/825= 0/8250_port.c > index 36b2b0a2c05c..a7acede62f40 100644 > --- a/drivers/tty/serial/8250/8250_port.c > +++ b/drivers/tty/serial/8250/8250_port.c > @@ -163,6 +163,7 @@ static const struct serial8250_config uart_config[] = =3D { > =09=09.fifo_size=09=3D 64, > =09=09.tx_loadsz=09=3D 64, > =09=09.fcr=09=09=3D UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, > +=09=09.rxtrig_bytes=09=3D {1, 16, 32, 62}, Reusing U6 entry for DW UARTs seems misleading. We've better mechanism coming up for defining rxtrig in a one pending=20 series so this constant friction with the uart config types can be put=20 into rest. Please build on top of that other series and help in testing and reviewing= =20 it. --=20 i. --8323328-656436369-1794236131=:1181--