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 739EA18DF60; Wed, 2 Oct 2024 13:50:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727877001; cv=none; b=Rcro7JpJJMhk5xWh9R2aRdP9c1sLOoxYRValf1sHe5d5HavU0mjrS8XV+RIqQ6Ctjk02SWHrLenlKjHAw3DQdKMtRK3GSut2XXjUj1A4Ka4qbjUk8DXUcUcLYcJx+meVvPrpBk7qApctbFgmxJGWLxr+8CtEXilGd4fBks/MpZs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727877001; c=relaxed/simple; bh=jjkcJcgpHKB01itnZK57CGckHlKGfKxrAxymtWZp2t0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Xzt2dBNAUCyCFQcLKOl5R3AJLuQcslqAk15Qv2qa706CGdSBf92adSeAPYDI1Mxkz6XM5SQuVBE8P3LLMe7L1DnITq/2ctXlfu63p9hlV/L4KJ5T1MInIf1xwd2fV4pP+SluBJuLlMQt3+DBN7ammmprdEoqnjIPlLth4CIq3JY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=r7L25sM4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="r7L25sM4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A6BBC4CEC2; Wed, 2 Oct 2024 13:50:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1727877000; bh=jjkcJcgpHKB01itnZK57CGckHlKGfKxrAxymtWZp2t0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r7L25sM4QMr8vfk+bJCn8neXuWXJfOnkPT8TERWB3o8mrbks+7nHoUeItDpcLRnHX yso8jKYbBai9O9jwzrVzQS57M3CRfU0MwD+lAxFJ3cdrhYP9HcN//y0TdHr1iHaqeY vc5haZZ0dtlyk88itPxqEDVaC+SkcBg0JEGXzJ4s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Douglas Anderson , "=?UTF-8?q?N=C3=ADcolas=20F . =20R . =20A . =20Prado?=" , Johan Hovold Subject: [PATCH 6.11 599/695] serial: qcom-geni: fix false console tx restart Date: Wed, 2 Oct 2024 14:59:57 +0200 Message-ID: <20241002125846.424094163@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241002125822.467776898@linuxfoundation.org> References: <20241002125822.467776898@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit f97cdbbf187fefcf1fe19689cd9fdca11fe9c3eb upstream. Commit 663abb1a7a7f ("tty: serial: qcom_geni_serial: Fix UART hang") addressed an issue with stalled tx after the console code interrupted the last bytes of a tx command by reenabling the watermark interrupt if there is data in write buffer. This can however break software flow control by re-enabling tx after the user has stopped it. Address the original issue by not clearing the CMD_DONE flag after polling for command completion. This allows the interrupt handler to start another transfer when the CMD_DONE interrupt has not been disabled due to flow control. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Fixes: 663abb1a7a7f ("tty: serial: qcom_geni_serial: Fix UART hang") Cc: stable@vger.kernel.org # 4.17 Reviewed-by: Douglas Anderson Tested-by: Nícolas F. R. A. Prado Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20240906131336.23625-3-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/qcom_geni_serial.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -306,18 +306,16 @@ static void qcom_geni_serial_setup_tx(st static void qcom_geni_serial_poll_tx_done(struct uart_port *uport) { int done; - u32 irq_clear = M_CMD_DONE_EN; done = qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, M_CMD_DONE_EN, true); if (!done) { writel(M_GENI_CMD_ABORT, uport->membase + SE_GENI_M_CMD_CTRL_REG); - irq_clear |= M_CMD_ABORT_EN; qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, M_CMD_ABORT_EN, true); + writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); } - writel(irq_clear, uport->membase + SE_GENI_M_IRQ_CLEAR); } static void qcom_geni_serial_abort_rx(struct uart_port *uport) @@ -378,6 +376,7 @@ static void qcom_geni_serial_poll_put_ch unsigned char c) { writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG); + writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); qcom_geni_serial_setup_tx(uport, 1); WARN_ON(!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, M_TX_FIFO_WATERMARK_EN, true)); @@ -422,6 +421,7 @@ __qcom_geni_serial_console_write(struct } writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG); + writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); qcom_geni_serial_setup_tx(uport, bytes_to_send); for (i = 0; i < count; ) { size_t chars_to_write = 0; @@ -463,7 +463,6 @@ static void qcom_geni_serial_console_wri bool locked = true; unsigned long flags; u32 geni_status; - u32 irq_en; WARN_ON(co->index < 0 || co->index >= GENI_UART_CONS_PORTS); @@ -495,12 +494,6 @@ static void qcom_geni_serial_console_wri * has been sent, in which case we need to look for done first. */ qcom_geni_serial_poll_tx_done(uport); - - if (!kfifo_is_empty(&uport->state->port.xmit_fifo)) { - irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN); - writel(irq_en | M_TX_FIFO_WATERMARK_EN, - uport->membase + SE_GENI_M_IRQ_EN); - } } __qcom_geni_serial_console_write(uport, s, count);