From patchwork Sat Oct 6 12:42:03 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Russell King X-Patchwork-Id: 1557411 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id A012CDF238 for ; Sat, 6 Oct 2012 12:43:51 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TKTht-0002WX-3S; Sat, 06 Oct 2012 12:42:13 +0000 Received: from [2002:4e20:1eda::1] (helo=caramon.arm.linux.org.uk) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TKThq-0002Vo-FV for linux-arm-kernel@lists.infradead.org; Sat, 06 Oct 2012 12:42:11 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=arm.linux.org.uk; s=caramon; h=Date:Sender:Message-Id:Subject:Cc:To:From:References:In-Reply-To; bh=TdbHTYfgL23dtUmyS11lgQM6guRSCO+fAvjNrMVGIlg=; b=FDzwyHldLRK72WFW73nxjC30ntkfHHK12H2fXDkseawKGf+vu2u2S6X8Idj2yBk5J03k7p+WrnhDlNFLLnoZieI5nATROtV2b97cKVycvOnnKnzcpzmpXouQ+BPHl967KMglwTeL2VWqtvA08vIaoapTV8Z72tYOr3mgrL+F/y4=; Received: from e0022681537dd.dyn.arm.linux.org.uk ([2002:4e20:1eda:1:222:68ff:fe15:37dd]:39598 helo=rmk-PC.arm.linux.org.uk) by caramon.arm.linux.org.uk with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.76) (envelope-from ) id 1TKThk-00087l-Dc; Sat, 06 Oct 2012 13:42:04 +0100 Received: from rmk by rmk-PC.arm.linux.org.uk with local (Exim 4.76) (envelope-from ) id 1TKThj-0002mw-IE; Sat, 06 Oct 2012 13:42:03 +0100 In-Reply-To: <20121006123803.GD15246@n2100.arm.linux.org.uk> References: <20121006123803.GD15246@n2100.arm.linux.org.uk> From: Russell King To: Tony Lindgren , Alan Cox , Greg Kroah-Hartman Subject: [RFC 09/24] SERIAL: core: add hardware assisted s/w flow control support Message-Id: Date: Sat, 06 Oct 2012 13:42:03 +0100 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -1.2 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.8 RDNS_NONE Delivered to internal network by a host with no rDNS Cc: linux-omap@vger.kernel.org, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Ports which are capable of handling s/w flow control in hardware to know when the s/w flow control termios settings are changed. Add a flag to allow the low level serial drivers to indicate that they support this, and these changes should be propagated to them. Signed-off-by: Russell King --- drivers/tty/serial/serial_core.c | 16 ++++++++++++++-- include/linux/serial_core.h | 2 ++ 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 95e6e32..ec6d029 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1197,7 +1197,19 @@ static void uart_set_termios(struct tty_struct *tty, struct uart_port *uport = state->uart_port; unsigned long flags; unsigned int cflag = tty->termios->c_cflag; + unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK; + bool sw_changed = false; + /* + * Drivers doing software flow control also need to know + * about changes to these input settings. + */ + if (uport->flags & UPF_SOFT_FLOW) { + iflag_mask |= IXANY|IXON|IXOFF; + sw_changed = + tty->termios->c_cc[VSTART] != old_termios->c_cc[VSTART] || + tty->termios->c_cc[VSTOP] != old_termios->c_cc[VSTOP]; + } /* * These are the bits that are used to setup various @@ -1205,11 +1217,11 @@ static void uart_set_termios(struct tty_struct *tty, * bits in c_cflag; c_[io]speed will always be set * appropriately by set_termios() in tty_ioctl.c */ -#define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK)) if ((cflag ^ old_termios->c_cflag) == 0 && tty->termios->c_ospeed == old_termios->c_ospeed && tty->termios->c_ispeed == old_termios->c_ispeed && - RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) { + ((tty->termios->c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 && + !sw_changed) { return; } diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 0253c20..be3f8d9 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -356,6 +356,8 @@ struct uart_port { #define UPF_BUGGY_UART ((__force upf_t) (1 << 14)) #define UPF_NO_TXEN_TEST ((__force upf_t) (1 << 15)) #define UPF_MAGIC_MULTIPLIER ((__force upf_t) (1 << 16)) +/* Port has hardware-assisted s/w flow control */ +#define UPF_SOFT_FLOW ((__force upf_t) (1 << 22)) #define UPF_CONS_FLOW ((__force upf_t) (1 << 23)) #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24)) #define UPF_EXAR_EFR ((__force upf_t) (1 << 25))