From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3A3AA2868BD; Tue, 24 Jun 2025 11:05:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750763126; cv=none; b=f19jVXYxi5JC1YzPhPVsrNA1wifKbAjx3LllDgppA5pOpMVDx59k40jPs2OOBOTO2FgfS5z2m5+6wF08THNCb0pMaxSMmR3SSRlju0C53bT+/AkwaYMhwQN9nrs4ZL6EGUPdbre9r5Y1O8B1E55uQpAKENr831JPQzm8oYXp8RM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750763126; c=relaxed/simple; bh=J17QCFM0YmsTh7lSotIGCixJIQqf5DkpQr93wgTxfE8=; h=From:Date:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=njxxsKWLlbwIU8E9v5fnoZSMxOsLOl2yoGfpUBdz571zlKY3zc+ZBi8X4aiQ0PCwKezXM4S6oonZt2ElWj2Q1LVw844RwSMy+d6nvifTUDHDcY0FMmqPoxvaILMhGVbkjSxFfebYeleDny4bVLMiaHDTE67CY0Q40RC8buiDy9w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=SlMVtvbv; arc=none smtp.client-ip=192.198.163.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="SlMVtvbv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1750763125; x=1782299125; h=from:date:to:cc:subject:in-reply-to:message-id: references:mime-version:content-id; bh=J17QCFM0YmsTh7lSotIGCixJIQqf5DkpQr93wgTxfE8=; b=SlMVtvbviUrlougH0bdvR2zs96AtdePUkW00hfLz7oBo41PK/n+tQ/gg RWMXaQHQWmjPVnwU4kVue0ekKqpdaFt2/ExzZyn+y9alou6caK5OkMRgt pLiQSf5pn2D46uTmNwLiTkgGn7YsLNEoiuMjSQfYeDt3fHDugClnfPGQ4 UtPtDwQnPxDJSQSBeGgCYaOWyUL2sH5Y5AnFEAN3qKFGR7swaZYXVa8XY +ANH2/PNUxlqw+47+Re8rgxHxEiWjS9W/5jxuBcQwqd/yWl/lbh/JcjSI 2pIw1tw/tjjzX1GP9X4yXXe8sGzrPP0IqRUoyws12eVQ2dMIljBqX+/v2 A==; X-CSE-ConnectionGUID: 3bv6vhefSQizxMbA7AJ+ew== X-CSE-MsgGUID: PP3FgOVgRMa+kEKyN8bbbQ== X-IronPort-AV: E=McAfee;i="6800,10657,11473"; a="40613102" X-IronPort-AV: E=Sophos;i="6.16,261,1744095600"; d="scan'208";a="40613102" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jun 2025 04:05:24 -0700 X-CSE-ConnectionGUID: fUp4ee/0Rb2k8XdbB2gTCQ== X-CSE-MsgGUID: zCYXp7LhTduHB/9ru6yNew== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,261,1744095600"; d="scan'208";a="152177842" Received: from ijarvine-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.245.16]) by fmviesa009-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jun 2025 04:05:22 -0700 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Tue, 24 Jun 2025 14:05:18 +0300 (EEST) To: "Jiri Slaby (SUSE)" cc: Greg Kroah-Hartman , linux-serial , LKML Subject: Re: [PATCH v2 2/5] serial: 8250: extract serial8250_iir_txen_test() In-Reply-To: <20250624080641.509959-3-jirislaby@kernel.org> Message-ID: References: <20250624080641.509959-1-jirislaby@kernel.org> <20250624080641.509959-3-jirislaby@kernel.org> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/mixed; BOUNDARY="8323328-1579240240-1750763032=:943" Content-ID: This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323328-1579240240-1750763032=:943 Content-Type: text/plain; CHARSET=ISO-8859-15 Content-Transfer-Encoding: QUOTED-PRINTABLE Content-ID: On Tue, 24 Jun 2025, Jiri Slaby (SUSE) wrote: > After commit 795158691cc0 ("serial: 8250: extract > serial8250_initialize()"), split serial8250_initialize() even more -- > the TX enable test part of this code can be separated into > serial8250_iir_txen_test(). >=20 > Signed-off-by: Jiri Slaby (SUSE) > Suggested-by: Ilpo J=E4rvinen > --- > drivers/tty/serial/8250/8250_port.c | 49 ++++++++++++++++------------- > 1 file changed, 28 insertions(+), 21 deletions(-) >=20 > diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/825= 0/8250_port.c > index 0f85a2f292fc..5bb0ca04da55 100644 > --- a/drivers/tty/serial/8250/8250_port.c > +++ b/drivers/tty/serial/8250/8250_port.c > @@ -2230,16 +2230,19 @@ static void serial8250_init_mctrl(struct uart_por= t *port) > =09serial8250_set_mctrl(port, port->mctrl); > } > =20 > -static void serial8250_initialize(struct uart_port *port) > +static void serial8250_iir_txen_test(struct uart_port *port) > { > =09struct uart_8250_port *up =3D up_to_u8250p(port); > -=09unsigned long flags; > =09bool lsr_TEMT, iir_NOINT; > =20 > -=09serial_port_out(port, UART_LCR, UART_LCR_WLEN8); > +=09if (port->quirks & UPQ_NO_TXEN_TEST) > +=09=09return; > =20 > -=09uart_port_lock_irqsave(port, &flags); > -=09serial8250_init_mctrl(port); > +=09/* Do a quick test to see if we receive an interrupt when we enable t= he TX irq. */ > +=09serial_port_out(port, UART_IER, UART_IER_THRI); > +=09lsr_TEMT =3D serial_port_in(port, UART_LSR) & UART_LSR_TEMT; > +=09iir_NOINT =3D serial_port_in(port, UART_IIR) & UART_IIR_NO_INT; > +=09serial_port_out(port, UART_IER, 0); > =20 > =09/* > =09 * Serial over Lan (SoL) hack: > @@ -2247,26 +2250,30 @@ static void serial8250_initialize(struct uart_por= t *port) > =09 * Lan. Those chips take a longer time than a normal serial device t= o signalize that a > =09 * transmission data was queued. Due to that, the above test generall= y fails. One solution > =09 * would be to delay the reading of iir. However, this is not reliabl= e, since the timeout is > -=09 * variable. So, let's just don't test if we receive TX irq. This wa= y, we'll never enable > -=09 * UART_BUG_TXEN. > +=09 * variable. So, in case of UPQ_NO_TXEN_TEST, let's just don't test i= f we receive TX irq. > +=09 * This way, we'll never enable UART_BUG_TXEN. > =09 */ > -=09if (!(port->quirks & UPQ_NO_TXEN_TEST)) { > -=09=09/* Do a quick test to see if we receive an interrupt when we enabl= e the TX irq. */ > -=09=09serial_port_out(port, UART_IER, UART_IER_THRI); > -=09=09lsr_TEMT =3D serial_port_in(port, UART_LSR) & UART_LSR_TEMT; > -=09=09iir_NOINT =3D serial_port_in(port, UART_IIR) & UART_IIR_NO_INT; > -=09=09serial_port_out(port, UART_IER, 0); > - > -=09=09if (lsr_TEMT && iir_NOINT) { > -=09=09=09if (!(up->bugs & UART_BUG_TXEN)) { > -=09=09=09=09up->bugs |=3D UART_BUG_TXEN; > -=09=09=09=09dev_dbg(port->dev, "enabling bad tx status workarounds\n"); > -=09=09=09} > -=09=09} else { > -=09=09=09up->bugs &=3D ~UART_BUG_TXEN; > +=09if (lsr_TEMT && iir_NOINT) { > +=09=09if (!(up->bugs & UART_BUG_TXEN)) { > +=09=09=09up->bugs |=3D UART_BUG_TXEN; > +=09=09=09dev_dbg(port->dev, "enabling bad tx status workarounds\n"); > =09=09} > +=09=09return; > =09} > =20 > +=09/* FIXME: why is this needed? */ > +=09up->bugs &=3D ~UART_BUG_TXEN; > +} > + > +static void serial8250_initialize(struct uart_port *port) > +{ > +=09unsigned long flags; > + > +=09serial_port_out(port, UART_LCR, UART_LCR_WLEN8); > + > +=09uart_port_lock_irqsave(port, &flags); > +=09serial8250_init_mctrl(port); > +=09serial8250_iir_txen_test(port); > =09uart_port_unlock_irqrestore(port, flags); > } > =20 >=20 Reviewed-by: Ilpo J=E4rvinen --=20 i. --8323328-1579240240-1750763032=:943--