From patchwork Mon Nov 15 08:42:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 12618931 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0C5AC433F5 for ; Mon, 15 Nov 2021 08:42:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DED5E61BF8 for ; Mon, 15 Nov 2021 08:42:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233752AbhKOIpc (ORCPT ); Mon, 15 Nov 2021 03:45:32 -0500 Received: from muru.com ([72.249.23.125]:56456 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236413AbhKOIp1 (ORCPT ); Mon, 15 Nov 2021 03:45:27 -0500 Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 8FBEE826C; Mon, 15 Nov 2021 08:43:07 +0000 (UTC) From: Tony Lindgren To: Greg Kroah-Hartman Cc: Andy Shevchenko , Jiri Slaby , Johan Hovold , Sebastian Andrzej Siewior , Vignesh Raghavendra , linux-serial@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, Andy Shevchenko Subject: [PATCH 7/7] serial: 8250_port: Remove calls to runtime PM Date: Mon, 15 Nov 2021 10:42:03 +0200 Message-Id: <20211115084203.56478-8-tony@atomide.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115084203.56478-1-tony@atomide.com> References: <20211115084203.56478-1-tony@atomide.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org From: Andy Shevchenko Since we now have runtime PM calls in serial_core.c the individual drivers do not need them anymore for the struct uart_ops related functions. Remove runtime PM calls in 8250 driver. This still leaves the flag for UART_CAP_RPM for serial8250_rpm_get_tx(), serial8250_rpm_put_tx() and serial8250_wakeup() to manage the reference count for serial TX. Signed-off-by: Andy Shevchenko [tony@atomide.com: updated to remove the exported functions too] Signed-off-by: Tony Lindgren --- drivers/tty/serial/8250/8250.h | 3 - drivers/tty/serial/8250/8250_port.c | 98 ++++++++--------------------- 2 files changed, 27 insertions(+), 74 deletions(-) diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h --- a/drivers/tty/serial/8250/8250.h +++ b/drivers/tty/serial/8250/8250.h @@ -152,9 +152,6 @@ static inline bool serial8250_clear_THRI(struct uart_8250_port *up) struct uart_8250_port *serial8250_get_port(int line); -void serial8250_rpm_get(struct uart_8250_port *p); -void serial8250_rpm_put(struct uart_8250_port *p); - void serial8250_rpm_get_tx(struct uart_8250_port *p); void serial8250_rpm_put_tx(struct uart_8250_port *p); diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -573,23 +573,6 @@ void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p) } EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos); -void serial8250_rpm_get(struct uart_8250_port *p) -{ - if (!(p->capabilities & UART_CAP_RPM)) - return; - pm_runtime_get_sync(p->port.dev); -} -EXPORT_SYMBOL_GPL(serial8250_rpm_get); - -void serial8250_rpm_put(struct uart_8250_port *p) -{ - if (!(p->capabilities & UART_CAP_RPM)) - return; - pm_runtime_mark_last_busy(p->port.dev); - pm_runtime_put_autosuspend(p->port.dev); -} -EXPORT_SYMBOL_GPL(serial8250_rpm_put); - /** * serial8250_em485_init() - put uart_8250_port into rs485 emulating * @p: uart_8250_port port instance @@ -724,7 +707,14 @@ void serial8250_rpm_get_tx(struct uart_8250_port *p) rpm_active = xchg(&p->rpm_tx_active, 1); if (rpm_active) return; - pm_runtime_get(p->port.dev); + + /* + * Device has to be powered on at this point. Here we just increase + * reference count to prevent autosuspend until the TX FIFO becomes + * empty. Paired with serial8250_rpm_put_tx(). See also a comment + * in serial8250_tx_chars(). + */ + pm_runtime_get_noresume(p->port.dev); } EXPORT_SYMBOL_GPL(serial8250_rpm_get_tx); @@ -752,8 +742,6 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) { unsigned char lcr = 0, efr = 0; - serial8250_rpm_get(p); - if (p->capabilities & UART_CAP_SLEEP) { if (p->capabilities & UART_CAP_EFR) { lcr = serial_in(p, UART_LCR); @@ -769,8 +757,6 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) serial_out(p, UART_LCR, lcr); } } - - serial8250_rpm_put(p); } #ifdef CONFIG_SERIAL_8250_RSA @@ -1432,13 +1418,9 @@ static void serial8250_stop_rx(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); - serial8250_rpm_get(up); - up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); up->port.read_status_mask &= ~UART_LSR_DR; serial_port_out(port, UART_IER, up->ier); - - serial8250_rpm_put(up); } /** @@ -1477,8 +1459,11 @@ static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t) stop_tx_timer); struct uart_8250_port *p = em485->port; unsigned long flags; + int err; - serial8250_rpm_get(p); + err = pm_runtime_resume_and_get(p->port.dev); + if (err < 0) + goto out_rpm_err; spin_lock_irqsave(&p->port.lock, flags); if (em485->active_timer == &em485->stop_tx_timer) { p->rs485_stop_tx(p); @@ -1486,8 +1471,9 @@ static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t) em485->tx_stopped = true; } spin_unlock_irqrestore(&p->port.lock, flags); - serial8250_rpm_put(p); - + pm_runtime_mark_last_busy(p->port.dev); + pm_runtime_put_autosuspend(p->port.dev); +out_rpm_err: return HRTIMER_NORESTART; } @@ -1545,7 +1531,6 @@ static void serial8250_stop_tx(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); - serial8250_rpm_get(up); __stop_tx(up); /* @@ -1555,7 +1540,6 @@ static void serial8250_stop_tx(struct uart_port *port) up->acr |= UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } - serial8250_rpm_put(up); } static inline void __start_tx(struct uart_port *port) @@ -1703,9 +1687,7 @@ static void serial8250_enable_ms(struct uart_port *port) up->ier |= UART_IER_MSI; - serial8250_rpm_get(up); serial_port_out(port, UART_IER, up->ier); - serial8250_rpm_put(up); } void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr) @@ -1984,15 +1966,11 @@ static unsigned int serial8250_tx_empty(struct uart_port *port) unsigned long flags; unsigned int lsr; - serial8250_rpm_get(up); - 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); - serial8250_rpm_put(up); - return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0; } @@ -2002,9 +1980,7 @@ unsigned int serial8250_do_get_mctrl(struct uart_port *port) unsigned int status; unsigned int val; - serial8250_rpm_get(up); status = serial8250_modem_status(up); - serial8250_rpm_put(up); val = serial8250_MSR_to_TIOCM(status); if (up->gpios) @@ -2054,7 +2030,6 @@ static void serial8250_break_ctl(struct uart_port *port, int break_state) struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; - serial8250_rpm_get(up); spin_lock_irqsave(&port->lock, flags); if (break_state == -1) up->lcr |= UART_LCR_SBC; @@ -2062,7 +2037,6 @@ 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); - serial8250_rpm_put(up); } /* @@ -2107,33 +2081,21 @@ static void wait_for_xmitr(struct uart_8250_port *up, int bits) static int serial8250_get_poll_char(struct uart_port *port) { - struct uart_8250_port *up = up_to_u8250p(port); unsigned char lsr; - int status; - - serial8250_rpm_get(up); lsr = serial_port_in(port, UART_LSR); + if (!(lsr & UART_LSR_DR)) + return NO_POLL_CHAR; - if (!(lsr & UART_LSR_DR)) { - status = NO_POLL_CHAR; - goto out; - } - - status = serial_port_in(port, UART_RX); -out: - serial8250_rpm_put(up); - return status; + return serial_port_in(port, UART_RX); } - static void serial8250_put_poll_char(struct uart_port *port, unsigned char c) { unsigned int ier; struct uart_8250_port *up = up_to_u8250p(port); - serial8250_rpm_get(up); /* * First save the IER then disable the interrupts */ @@ -2155,7 +2117,6 @@ static void serial8250_put_poll_char(struct uart_port *port, */ wait_for_xmitr(up, BOTH_EMPTY); serial_port_out(port, UART_IER, ier); - serial8250_rpm_put(up); } #endif /* CONFIG_CONSOLE_POLL */ @@ -2178,7 +2139,6 @@ int serial8250_do_startup(struct uart_port *port) if (port->iotype != up->cur_iotype) set_io_from_upio(port); - serial8250_rpm_get(up); if (port->type == PORT_16C950) { /* Wake up and initialize UART */ up->acr = 0; @@ -2244,8 +2204,7 @@ int serial8250_do_startup(struct uart_port *port) if (!(port->flags & UPF_BUGGY_UART) && (serial_port_in(port, UART_LSR) == 0xff)) { dev_info_ratelimited(port->dev, "LSR safety check engaged!\n"); - retval = -ENODEV; - goto out; + return -ENODEV; } /* @@ -2333,7 +2292,7 @@ int serial8250_do_startup(struct uart_port *port) retval = up->ops->setup_irq(up); if (retval) - goto out; + return retval; /* * Now, initialize the UART @@ -2432,10 +2391,7 @@ int serial8250_do_startup(struct uart_port *port) outb_p(0x80, icp); inb_p(icp); } - retval = 0; -out: - serial8250_rpm_put(up); - return retval; + return 0; } EXPORT_SYMBOL_GPL(serial8250_do_startup); @@ -2451,7 +2407,6 @@ void serial8250_do_shutdown(struct uart_port *port) struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; - serial8250_rpm_get(up); /* * Disable interrupts from this port */ @@ -2495,7 +2450,6 @@ void serial8250_do_shutdown(struct uart_port *port) * the IRQ chain. */ serial_port_in(port, UART_RX); - serial8250_rpm_put(up); up->ops->release_irq(up); } @@ -2737,6 +2691,7 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk) unsigned int baud, quot, frac = 0; struct ktermios *termios; unsigned long flags; + int err; mutex_lock(&port->state->port.mutex); @@ -2753,7 +2708,9 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk) baud = serial8250_get_baud_rate(port, termios, NULL); quot = serial8250_get_divisor(port, baud, &frac); - serial8250_rpm_get(up); + err = pm_runtime_resume_and_get(port->dev); + if (err < 0) + goto out_lock; spin_lock_irqsave(&port->lock, flags); uart_update_timeout(port, termios->c_cflag, baud); @@ -2762,7 +2719,8 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk) serial_port_out(port, UART_LCR, up->lcr); spin_unlock_irqrestore(&port->lock, flags); - serial8250_rpm_put(up); + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); out_lock: mutex_unlock(&port->state->port.mutex); @@ -2793,7 +2751,6 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, * Ok, we're now changing the port state. Do it with * interrupts disabled. */ - serial8250_rpm_get(up); spin_lock_irqsave(&port->lock, flags); up->lcr = cval; /* Save computed LCR */ @@ -2899,7 +2856,6 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, } serial8250_set_mctrl(port, port->mctrl); spin_unlock_irqrestore(&port->lock, flags); - serial8250_rpm_put(up); /* Don't rewrite B0 */ if (tty_termios_baud_rate(termios))