From patchwork Wed May 12 14:43:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 438045 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B02BDC2B9FF for ; Wed, 12 May 2021 16:37:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 90E2B60BBB for ; Wed, 12 May 2021 16:37:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237079AbhELQiA (ORCPT ); Wed, 12 May 2021 12:38:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:43696 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236017AbhELQ22 (ORCPT ); Wed, 12 May 2021 12:28:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1349B613EB; Wed, 12 May 2021 15:56:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620834986; bh=wpF9bj4uyWGgJtJyiv2VNMZQEBepVIvaGB5J8NY830M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e9iuLnSXyuEF69mychGR7GLpOXU4Tot0QcsxrOzrMXrTDU4MAyfJOzZe2EVzupQs+ 3EXT/uAfk5yv2VfhispnyMpKMHht/fA/n7BOU8nNLZbO++HtkEJyIzpi8ZsikkaT/J Zx7OwB+uNJ1lcuJoNHg7QsaVBsgJRo5htbqmlS3U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Erwan Le Ray , Sasha Levin Subject: [PATCH 5.12 164/677] serial: stm32: fix wake-up flag handling Date: Wed, 12 May 2021 16:43:30 +0200 Message-Id: <20210512144842.695159149@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144837.204217980@linuxfoundation.org> References: <20210512144837.204217980@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Erwan Le Ray [ Upstream commit 12761869f0efa524348e2ae31827fd52eebf3f0d ] This patch fixes several issue with wake-up handling: - the WUF irq is handled several times at wake-up - the USART is disabled / enabled at suspend to set wake-up flag. It can cause glitches during RX. This patch fix those issues: - clear wake-up flag and disable wake-up irq in WUF irq handling - enable wake-up from low power on start bit detection at port configuration - Unmask the wake-up flag irq at suspend and mask it at resume In addition, pm_wakeup_event handling is moved from receice_chars to WUF irq handling. Fixes: 270e5a74fe4c ("serial: stm32: add wakeup mechanism") Signed-off-by: Erwan Le Ray Link: https://lore.kernel.org/r/20210304162308.8984-7-erwan.leray@foss.st.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/stm32-usart.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 370141445780..326f300dd410 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -218,9 +218,6 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded) u32 sr; char flag; - if (irqd_is_wakeup_set(irq_get_irq_data(port->irq))) - pm_wakeup_event(tport->tty->dev, 0); - if (threaded) spin_lock_irqsave(&port->lock, flags); else @@ -463,6 +460,7 @@ static void stm32_usart_transmit_chars(struct uart_port *port) static irqreturn_t stm32_usart_interrupt(int irq, void *ptr) { struct uart_port *port = ptr; + struct tty_port *tport = &port->state->port; struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; u32 sr; @@ -473,9 +471,14 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr) writel_relaxed(USART_ICR_RTOCF, port->membase + ofs->icr); - if ((sr & USART_SR_WUF) && ofs->icr != UNDEF_REG) + if ((sr & USART_SR_WUF) && ofs->icr != UNDEF_REG) { + /* Clear wake up flag and disable wake up interrupt */ writel_relaxed(USART_ICR_WUCF, port->membase + ofs->icr); + stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_WUFIE); + if (irqd_is_wakeup_set(irq_get_irq_data(port->irq))) + pm_wakeup_event(tport->tty->dev, 0); + } if ((sr & USART_SR_RXNE) && !(stm32_port->rx_ch)) stm32_usart_receive_chars(port, false); @@ -901,6 +904,12 @@ static void stm32_usart_set_termios(struct uart_port *port, cr1 &= ~(USART_CR1_DEDT_MASK | USART_CR1_DEAT_MASK); } + /* Configure wake up from low power on start bit detection */ + if (stm32_port->wakeirq > 0) { + cr3 &= ~USART_CR3_WUS_MASK; + cr3 |= USART_CR3_WUS_START_BIT; + } + writel_relaxed(cr3, port->membase + ofs->cr3); writel_relaxed(cr2, port->membase + ofs->cr2); writel_relaxed(cr1, port->membase + ofs->cr1); @@ -1476,23 +1485,20 @@ static void __maybe_unused stm32_usart_serial_en_wakeup(struct uart_port *port, { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; - const struct stm32_usart_config *cfg = &stm32_port->info->cfg; - u32 val; if (stm32_port->wakeirq <= 0) return; + /* + * Enable low-power wake-up and wake-up irq if argument is set to + * "enable", disable low-power wake-up and wake-up irq otherwise + */ if (enable) { - stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); stm32_usart_set_bits(port, ofs->cr1, USART_CR1_UESM); - val = readl_relaxed(port->membase + ofs->cr3); - val &= ~USART_CR3_WUS_MASK; - /* Enable Wake up interrupt from low power on start bit */ - val |= USART_CR3_WUS_START_BIT | USART_CR3_WUFIE; - writel_relaxed(val, port->membase + ofs->cr3); - stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); + stm32_usart_set_bits(port, ofs->cr3, USART_CR3_WUFIE); } else { stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_UESM); + stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_WUFIE); } }