From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9C6A822F0C for ; Fri, 5 Jan 2024 09:23:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nNVp4SAI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FB1AC433C8; Fri, 5 Jan 2024 09:23:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1704446583; bh=tTAURM1kBr6TB8Y58n+ejaHY9X43ZfDXYAsrP1qb1qw=; h=Subject:To:From:Date:From; b=nNVp4SAI2dtEI2KzZcWvQMUWThVP25D0Osqcm4GCtqNhkZYhBqQn4NIpMggB04GMx 6+l431Hgplie4COTAlYfhLaZFGGJMEcxVDaema9RfrPEzNFGhb4l8b17whTryi1otZ M0N4GRFEiJgNgiq133hOHz5I325+2XcEobegkCus= Subject: patch "serial: sc16is7xx: remove obsolete loop in sc16is7xx_port_irq()" added to tty-next To: hvilleneuve@dimonoff.com,andy.shevchenko@gmail.com,gregkh@linuxfoundation.org,stable@vger.kernel.org From: Date: Fri, 05 Jan 2024 10:21:55 +0100 Message-ID: <2024010555-uncapped-pancake-deaa@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit This is a note to let you know that I've just added the patch titled serial: sc16is7xx: remove obsolete loop in sc16is7xx_port_irq() to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-next branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will also be merged in the next major kernel release during the merge window. If you have any questions about this process, please let me know. >From ed647256e8f226241ecff7baaecdb8632ffc7ec1 Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve Date: Thu, 21 Dec 2023 18:18:11 -0500 Subject: serial: sc16is7xx: remove obsolete loop in sc16is7xx_port_irq() Commit 834449872105 ("sc16is7xx: Fix for multi-channel stall") changed sc16is7xx_port_irq() from looping multiple times when there was still interrupts to serve. It simply changed the do {} while(1) loop to a do {} while(0) loop, which makes the loop itself now obsolete. Clean the code by removing this obsolete do {} while(0) loop. Fixes: 834449872105 ("sc16is7xx: Fix for multi-channel stall") Cc: Suggested-by: Andy Shevchenko Signed-off-by: Hugo Villeneuve Link: https://lore.kernel.org/r/20231221231823.2327894-5-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sc16is7xx.c | 81 ++++++++++++++++------------------ 1 file changed, 39 insertions(+), 42 deletions(-) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index ced2446909a2..44a11c89c949 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -725,58 +725,55 @@ static void sc16is7xx_update_mlines(struct sc16is7xx_one *one) static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno) { bool rc = true; + unsigned int iir, rxlen; struct uart_port *port = &s->p[portno].port; struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); mutex_lock(&one->efr_lock); - do { - unsigned int iir, rxlen; + iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG); + if (iir & SC16IS7XX_IIR_NO_INT_BIT) { + rc = false; + goto out_port_irq; + } - iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG); - if (iir & SC16IS7XX_IIR_NO_INT_BIT) { - rc = false; - goto out_port_irq; - } + iir &= SC16IS7XX_IIR_ID_MASK; - iir &= SC16IS7XX_IIR_ID_MASK; + switch (iir) { + case SC16IS7XX_IIR_RDI_SRC: + case SC16IS7XX_IIR_RLSE_SRC: + case SC16IS7XX_IIR_RTOI_SRC: + case SC16IS7XX_IIR_XOFFI_SRC: + rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG); - switch (iir) { - case SC16IS7XX_IIR_RDI_SRC: - case SC16IS7XX_IIR_RLSE_SRC: - case SC16IS7XX_IIR_RTOI_SRC: - case SC16IS7XX_IIR_XOFFI_SRC: - rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG); + /* + * There is a silicon bug that makes the chip report a + * time-out interrupt but no data in the FIFO. This is + * described in errata section 18.1.4. + * + * When this happens, read one byte from the FIFO to + * clear the interrupt. + */ + if (iir == SC16IS7XX_IIR_RTOI_SRC && !rxlen) + rxlen = 1; - /* - * There is a silicon bug that makes the chip report a - * time-out interrupt but no data in the FIFO. This is - * described in errata section 18.1.4. - * - * When this happens, read one byte from the FIFO to - * clear the interrupt. - */ - if (iir == SC16IS7XX_IIR_RTOI_SRC && !rxlen) - rxlen = 1; - - if (rxlen) - sc16is7xx_handle_rx(port, rxlen, iir); - break; + if (rxlen) + sc16is7xx_handle_rx(port, rxlen, iir); + break; /* CTSRTS interrupt comes only when CTS goes inactive */ - case SC16IS7XX_IIR_CTSRTS_SRC: - case SC16IS7XX_IIR_MSI_SRC: - sc16is7xx_update_mlines(one); - break; - case SC16IS7XX_IIR_THRI_SRC: - sc16is7xx_handle_tx(port); - break; - default: - dev_err_ratelimited(port->dev, - "ttySC%i: Unexpected interrupt: %x", - port->line, iir); - break; - } - } while (0); + case SC16IS7XX_IIR_CTSRTS_SRC: + case SC16IS7XX_IIR_MSI_SRC: + sc16is7xx_update_mlines(one); + break; + case SC16IS7XX_IIR_THRI_SRC: + sc16is7xx_handle_tx(port); + break; + default: + dev_err_ratelimited(port->dev, + "ttySC%i: Unexpected interrupt: %x", + port->line, iir); + break; + } out_port_irq: mutex_unlock(&one->efr_lock); -- 2.43.0