From patchwork Thu Dec 13 18:44:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 10729601 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 363F33E9D for ; Thu, 13 Dec 2018 18:44:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 284CB2C84A for ; Thu, 13 Dec 2018 18:44:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1CEF52C83E; Thu, 13 Dec 2018 18:44:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CE9702C84D for ; Thu, 13 Dec 2018 18:44:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726764AbeLMSos (ORCPT ); Thu, 13 Dec 2018 13:44:48 -0500 Received: from michel.telenet-ops.be ([195.130.137.88]:57182 "EHLO michel.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726630AbeLMSor (ORCPT ); Thu, 13 Dec 2018 13:44:47 -0500 Received: from ramsan ([84.194.111.163]) by michel.telenet-ops.be with bizsmtp id BWkl1z00m3XaVaC06WklEH; Thu, 13 Dec 2018 19:44:46 +0100 Received: from rox.of.borg ([192.168.97.57]) by ramsan with esmtp (Exim 4.90_1) (envelope-from ) id 1gXVyX-0007qu-F5; Thu, 13 Dec 2018 19:44:45 +0100 Received: from geert by rox.of.borg with local (Exim 4.90_1) (envelope-from ) id 1gXVyX-0005iD-Dz; Thu, 13 Dec 2018 19:44:45 +0100 From: Geert Uytterhoeven To: Greg Kroah-Hartman , Jiri Slaby Cc: Ulrich Hecht , Wolfram Sang , Yoshihiro Shimoda , Yoshinori Sato , linux-renesas-soc@vger.kernel.org, linux-sh@vger.kernel.org, linux-serial@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v4 3/4] serial: sh-sci: Resume PIO in sci_rx_interrupt() on DMA failure Date: Thu, 13 Dec 2018 19:44:43 +0100 Message-Id: <20181213184444.21904-4-geert+renesas@glider.be> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181213184444.21904-1-geert+renesas@glider.be> References: <20181213184444.21904-1-geert+renesas@glider.be> Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On (H)SCIF, sci_submit_rx() is called in the receive interrupt handler. Hence if DMA submission fails, the interrupt handler should resume handling reception using PIO, else no more data is received. Make sci_submit_rx() return an error indicator, so the receive interrupt handler can act appropriately. Signed-off-by: Geert Uytterhoeven Acked-by: Wolfram Sang Reviewed-by: Simon Horman --- v4: - Let sci_submit_rx() return -EAGAIN instead of -1 on failure, - Check for negative error in sci_submit_rx() caller, v3: - Move label handle_pio inside #ifdef to kill defined but not used compiler warning when CONFIG_SERIAL_SH_SCI_DMA=n, - Move the call sci_submit_rx() in sci_rx_interrupt() up, as it may fail, rendering the modification of scr unused, - Split in multiple patches. --- drivers/tty/serial/sh-sci.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index e353e03ce2602559..8df0fd8245203f8b 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1331,7 +1331,7 @@ static void sci_tx_dma_release(struct sci_port *s) dma_release_channel(chan); } -static void sci_submit_rx(struct sci_port *s, bool port_lock_held) +static int sci_submit_rx(struct sci_port *s, bool port_lock_held) { struct dma_chan *chan = s->chan_rx; struct uart_port *port = &s->port; @@ -1359,7 +1359,7 @@ static void sci_submit_rx(struct sci_port *s, bool port_lock_held) s->active_rx = s->cookie_rx[0]; dma_async_issue_pending(chan); - return; + return 0; fail: /* Switch to PIO */ @@ -1374,6 +1374,7 @@ static void sci_submit_rx(struct sci_port *s, bool port_lock_held) sci_start_rx(port); if (!port_lock_held) spin_unlock_irqrestore(&port->lock, flags); + return -EAGAIN; } static void work_fn_tx(struct work_struct *work) @@ -1668,8 +1669,10 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr) disable_irq_nosync(irq); scr |= SCSCR_RDRQE; } else { + if (sci_submit_rx(s, false) < 0) + goto handle_pio; + scr &= ~SCSCR_RIE; - sci_submit_rx(s, false); } serial_port_out(port, SCSCR, scr); /* Clear current interrupt */ @@ -1681,6 +1684,8 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr) return IRQ_HANDLED; } + +handle_pio: #endif if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {