From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765015AbZAONb0 (ORCPT ); Thu, 15 Jan 2009 08:31:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1764767AbZAONak (ORCPT ); Thu, 15 Jan 2009 08:30:40 -0500 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:60782 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1764750AbZAONai (ORCPT ); Thu, 15 Jan 2009 08:30:38 -0500 From: Alan Cox Subject: [PATCH 4/8] When a break signal is detected, the next character should be ignored. To: torvalds@linux-foundation.org, linux-kernel@vger.kernel.org Date: Thu, 15 Jan 2009 13:30:56 +0000 Message-ID: <20090115133050.21366.18907.stgit@localhost.localdomain> In-Reply-To: <20090115132718.21366.56187.stgit@localhost.localdomain> References: <20090115132718.21366.56187.stgit@localhost.localdomain> User-Agent: StGIT/0.14.2 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mischa Jonker This was not implemented correctly for the pnx8xxx_uart driver. [From further discussion: Correct, you can look to it as two separate bugs: a) the next character is not ignored while it should; b) the status bits 31-8 are copied to the 'ch' variable while they shouldn't. Both bugs prevent correct break signal handling (and therefore correct behaviour of the magic SysRq key). Bug b didn't cause too much trouble earlier because in most situations the status bits are all zero; for this case they unfortunately aren't. ] Signed-off-by: Mischa Jonker Signed-off-by: Alan Cox --- drivers/serial/pnx8xxx_uart.c | 23 ++++++++++++----------- 1 files changed, 12 insertions(+), 11 deletions(-) diff --git a/drivers/serial/pnx8xxx_uart.c b/drivers/serial/pnx8xxx_uart.c index 22e30d2..1bb8f1b 100644 --- a/drivers/serial/pnx8xxx_uart.c +++ b/drivers/serial/pnx8xxx_uart.c @@ -187,7 +187,7 @@ static void pnx8xxx_rx_chars(struct pnx8xxx_port *sport) status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) | ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT)); while (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFIFO)) { - ch = serial_in(sport, PNX8XXX_FIFO); + ch = serial_in(sport, PNX8XXX_FIFO) & 0xff; sport->port.icount.rx++; @@ -198,9 +198,16 @@ static void pnx8xxx_rx_chars(struct pnx8xxx_port *sport) * out of the main execution path */ if (status & (FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE | - PNX8XXX_UART_FIFO_RXPAR) | + PNX8XXX_UART_FIFO_RXPAR | + PNX8XXX_UART_FIFO_RXBRK) | ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN))) { - if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR)) + if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXBRK)) { + status &= ~(FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE) | + FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR)); + sport->port.icount.brk++; + if (uart_handle_break(&sport->port)) + goto ignore_char; + } else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR)) sport->port.icount.parity++; else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE)) sport->port.icount.frame++; @@ -284,14 +291,8 @@ static irqreturn_t pnx8xxx_int(int irq, void *dev_id) /* Get the interrupts */ status = serial_in(sport, PNX8XXX_ISTAT) & serial_in(sport, PNX8XXX_IEN); - /* Break signal received */ - if (status & PNX8XXX_UART_INT_BREAK) { - sport->port.icount.brk++; - uart_handle_break(&sport->port); - } - - /* Byte received */ - if (status & PNX8XXX_UART_INT_RX) + /* Byte or break signal received */ + if (status & (PNX8XXX_UART_INT_RX | PNX8XXX_UART_INT_BREAK)) pnx8xxx_rx_chars(sport); /* TX holding register empty - transmit a byte */