From patchwork Wed Jul 16 14:45:02 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 4567811 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 618AF9F295 for ; Wed, 16 Jul 2014 14:48:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3E877201C7 for ; Wed, 16 Jul 2014 14:48:53 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F3F23201B9 for ; Wed, 16 Jul 2014 14:48:51 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1X7QTm-0006JS-N9; Wed, 16 Jul 2014 14:46:46 +0000 Received: from galois.linutronix.de ([2001:470:1f0b:db:abcd:42:0:1]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1X7QSe-0005YN-KL for linux-arm-kernel@lists.infradead.org; Wed, 16 Jul 2014 14:45:39 +0000 Received: from localhost ([127.0.0.1] helo=bazinga.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1X7QSF-0000DT-Hy; Wed, 16 Jul 2014 16:45:11 +0200 From: Sebastian Andrzej Siewior To: linux-omap@vger.kernel.org Subject: [PATCH 4/5] tty: serial: 8250 core: add runtime pm Date: Wed, 16 Jul 2014 16:45:02 +0200 Message-Id: <1405521903-5877-5-git-send-email-bigeasy@linutronix.de> X-Mailer: git-send-email 2.0.1 In-Reply-To: <1405521903-5877-1-git-send-email-bigeasy@linutronix.de> References: <1405521903-5877-1-git-send-email-bigeasy@linutronix.de> MIME-Version: 1.0 X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1, SHORTCIRCUIT=-0.0001 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140716_074536_880928_4E428C34 X-CRM114-Status: GOOD ( 20.10 ) X-Spam-Score: -0.0 (/) Cc: Tony Lindgren , Greg Kroah-Hartman , Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org, Felipe Balbi , linux-serial@vger.kernel.org, mika.westerberg@linux.intel.com, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP While comparing the OMAP-serial and the 8250 part of this I noticed that the the latter does not use runtime-pm. Here are the pieces. It is basically a get before first register access and a last_busy + put after last access. If I understand this correct, it should do nothing as long as pm_runtime_use_autosuspend() + pm_runtime_enable() isn't invoked on the device. v3…v4: - added runtime to the console code - removed device_may_wakeup() from serial8250_set_sleep() Cc: mika.westerberg@linux.intel.com Signed-off-by: Sebastian Andrzej Siewior --- drivers/tty/serial/8250/8250_core.c | 98 ++++++++++++++++++++++++++++++++----- 1 file changed, 85 insertions(+), 13 deletions(-) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 714f954..aceaea1 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -38,6 +38,7 @@ #include #include #include +#include #ifdef CONFIG_SPARC #include #endif @@ -553,10 +554,11 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) * offset but the UART channel may only write to the corresponding * bit. */ + pm_runtime_get_sync(p->port.dev); if ((p->port.type == PORT_XR17V35X) || (p->port.type == PORT_XR17D15X)) { serial_out(p, UART_EXAR_SLEEP, sleep ? 0xff : 0); - return; + goto out; } if (p->capabilities & UART_CAP_SLEEP) { @@ -572,6 +574,9 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) serial_out(p, UART_LCR, 0); } } +out: + pm_runtime_mark_last_busy(p->port.dev); + pm_runtime_put_autosuspend(p->port.dev); } #ifdef CONFIG_SERIAL_8250_RSA @@ -1280,6 +1285,7 @@ static void serial8250_stop_tx(struct uart_port *port) struct uart_8250_port *up = container_of(port, struct uart_8250_port, port); + pm_runtime_get_sync(port->dev); __stop_tx(up); /* @@ -1289,6 +1295,8 @@ static void serial8250_stop_tx(struct uart_port *port) up->acr |= UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); } static void serial8250_start_tx(struct uart_port *port) @@ -1296,8 +1304,9 @@ static void serial8250_start_tx(struct uart_port *port) struct uart_8250_port *up = container_of(port, struct uart_8250_port, port); + pm_runtime_get_sync(port->dev); if (up->dma && !serial8250_tx_dma(up)) { - return; + goto out; } else if (!(up->ier & UART_IER_THRI)) { up->ier |= UART_IER_THRI; serial_port_out(port, UART_IER, up->ier); @@ -1318,6 +1327,9 @@ static void serial8250_start_tx(struct uart_port *port) up->acr &= ~UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } +out: + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); } static void serial8250_throttle(struct uart_port *port) @@ -1335,9 +1347,14 @@ static void serial8250_stop_rx(struct uart_port *port) struct uart_8250_port *up = container_of(port, struct uart_8250_port, port); + pm_runtime_get_sync(port->dev); + up->ier &= ~UART_IER_RLSI; up->port.read_status_mask &= ~UART_LSR_DR; serial_port_out(port, UART_IER, up->ier); + + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); } static void serial8250_enable_ms(struct uart_port *port) @@ -1350,7 +1367,10 @@ static void serial8250_enable_ms(struct uart_port *port) return; up->ier |= UART_IER_MSI; + pm_runtime_get_sync(port->dev); serial_port_out(port, UART_IER, up->ier); + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); } /* @@ -1540,9 +1560,17 @@ EXPORT_SYMBOL_GPL(serial8250_handle_irq); static int serial8250_default_handle_irq(struct uart_port *port) { - unsigned int iir = serial_port_in(port, UART_IIR); + unsigned int iir; + int ret; + + pm_runtime_get_sync(port->dev); + + iir = serial_port_in(port, UART_IIR); + ret = serial8250_handle_irq(port, iir); - return serial8250_handle_irq(port, iir); + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); + return ret; } /* @@ -1800,11 +1828,16 @@ static unsigned int serial8250_tx_empty(struct uart_port *port) unsigned long flags; unsigned int lsr; + pm_runtime_get_sync(port->dev); + spin_lock_irqsave(&port->lock, flags); lsr = serial_port_in(port, UART_LSR); up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; spin_unlock_irqrestore(&port->lock, flags); + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); + return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0; } @@ -1815,7 +1848,10 @@ static unsigned int serial8250_get_mctrl(struct uart_port *port) unsigned int status; unsigned int ret; + pm_runtime_get_sync(port->dev); status = serial8250_modem_status(up); + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); ret = 0; if (status & UART_MSR_DCD) @@ -1848,7 +1884,10 @@ static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl) mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr; + pm_runtime_get_sync(port->dev); serial_port_out(port, UART_MCR, mcr); + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); } static void serial8250_break_ctl(struct uart_port *port, int break_state) @@ -1857,6 +1896,7 @@ static void serial8250_break_ctl(struct uart_port *port, int break_state) container_of(port, struct uart_8250_port, port); unsigned long flags; + pm_runtime_get_sync(port->dev); spin_lock_irqsave(&port->lock, flags); if (break_state == -1) up->lcr |= UART_LCR_SBC; @@ -1864,6 +1904,8 @@ static void serial8250_break_ctl(struct uart_port *port, int break_state) up->lcr &= ~UART_LCR_SBC; serial_port_out(port, UART_LCR, up->lcr); spin_unlock_irqrestore(&port->lock, flags); + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); } /* @@ -1908,12 +1950,23 @@ static void wait_for_xmitr(struct uart_8250_port *up, int bits) static int serial8250_get_poll_char(struct uart_port *port) { - unsigned char lsr = serial_port_in(port, UART_LSR); + unsigned char lsr; + int status; - if (!(lsr & UART_LSR_DR)) - return NO_POLL_CHAR; + pm_runtime_get_sync(port->dev); - return serial_port_in(port, UART_RX); + lsr = serial_port_in(port, UART_LSR); + + if (!(lsr & UART_LSR_DR)) { + status = NO_POLL_CHAR; + goto out; + } + + status = serial_port_in(port, UART_RX); +out: + pm_runtime_mark_last_busy(up->dev); + pm_runtime_put_autosuspend(up->dev); + return status; } @@ -1924,6 +1977,7 @@ static void serial8250_put_poll_char(struct uart_port *port, struct uart_8250_port *up = container_of(port, struct uart_8250_port, port); + pm_runtime_get_sync(up->dev); /* * First save the IER then disable the interrupts */ @@ -1945,6 +1999,9 @@ static void serial8250_put_poll_char(struct uart_port *port, */ wait_for_xmitr(up, BOTH_EMPTY); serial_port_out(port, UART_IER, ier); + pm_runtime_mark_last_busy(up->dev); + pm_runtime_put_autosuspend(up->dev); + } #endif /* CONFIG_CONSOLE_POLL */ @@ -1971,6 +2028,7 @@ int serial8250_do_startup(struct uart_port *port) if (port->iotype != up->cur_iotype) set_io_from_upio(port); + pm_runtime_get_sync(port->dev); if (port->type == PORT_16C950) { /* Wake up and initialize UART */ up->acr = 0; @@ -1991,7 +2049,6 @@ int serial8250_do_startup(struct uart_port *port) */ enable_rsa(up); #endif - /* * Clear the FIFO buffers and disable them. * (they will be reenabled in set_termios()) @@ -2015,7 +2072,8 @@ int serial8250_do_startup(struct uart_port *port) (serial_port_in(port, UART_LSR) == 0xff)) { printk_ratelimited(KERN_INFO "ttyS%d: LSR safety check engaged!\n", serial_index(port)); - return -ENODEV; + retval = -ENODEV; + goto out; } /* @@ -2100,7 +2158,7 @@ int serial8250_do_startup(struct uart_port *port) } else { retval = serial_link_irq_chain(up); if (retval) - return retval; + goto out; } /* @@ -2198,8 +2256,11 @@ int serial8250_do_startup(struct uart_port *port) outb_p(0x80, icp); inb_p(icp); } - - return 0; + retval = 0; +out: + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); + return retval; } EXPORT_SYMBOL_GPL(serial8250_do_startup); @@ -2217,6 +2278,7 @@ void serial8250_do_shutdown(struct uart_port *port) container_of(port, struct uart_8250_port, port); unsigned long flags; + pm_runtime_get_sync(port->dev); /* * Disable interrupts from this port */ @@ -2256,6 +2318,8 @@ void serial8250_do_shutdown(struct uart_port *port) * the IRQ chain. */ serial_port_in(port, UART_RX); + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); del_timer_sync(&up->timer); up->timer.function = serial8250_timeout; @@ -2375,6 +2439,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, * Ok, we're now changing the port state. Do it with * interrupts disabled. */ + pm_runtime_get_sync(port->dev); spin_lock_irqsave(&port->lock, flags); /* @@ -2496,6 +2561,9 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, } serial8250_set_mctrl(port, port->mctrl); spin_unlock_irqrestore(&port->lock, flags); + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); + /* Don't rewrite B0 */ if (tty_termios_baud_rate(termios)) tty_termios_encode_baud_rate(termios, baud, baud); @@ -2931,6 +2999,8 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count) touch_nmi_watchdog(); + pm_runtime_get_sync(port->dev); + if (port->sysrq || oops_in_progress) locked = spin_trylock_irqsave(&port->lock, flags); else @@ -2967,6 +3037,8 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count) if (locked) spin_unlock_irqrestore(&port->lock, flags); + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); } static int __init serial8250_console_setup(struct console *co, char *options)