Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754451AbaFIXny (ORCPT ); Mon, 9 Jun 2014 19:43:54 -0400 Received: from mailout32.mail01.mtsvc.net ([216.70.64.70]:40612 "EHLO n23.mail01.mtsvc.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754051AbaFIXnx (ORCPT ); Mon, 9 Jun 2014 19:43:53 -0400 From: Peter Hurley To: Aaro Koskinen Cc: David Miller , linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, Greg Kroah-Hartman , Seth Bollinger , Peter Hurley Subject: On 06/09/2014 04:59 PM, Aaro Koskinen wrote:> Hi, Date: Mon, 9 Jun 2014 19:43:37 -0400 Message-Id: <1402357417-20746-1-git-send-email-peter@hurleysoftware.com> X-Mailer: git-send-email 2.0.0 In-Reply-To: <20140609205917.GA913@drone.musicnaut.iki.fi> References: <20140609205917.GA913@drone.musicnaut.iki.fi> X-Authenticated-User: 990527 peter@hurleysoftware.com X-MT-ID: 8FA290C2A27252AACF65DBC4A42F3CE3735FB2A4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks for the report Aaro. Looks like Seth's fix exposes some broken assumptions in the Sun serial drivers. Can you test the patch below? Regards, Peter Hurley PS - Do you have a way to test also your setup using hardware flow control, ie. CRTSCTS? I ask because I would expect that to be broken even before Seth's patch. --- %< --- From: Peter Hurley Date: Mon, 9 Jun 2014 19:21:43 -0400 Subject: [PATCH] serial: sunsab: Test for no tx data on tx restart Commit 717f3bbab3c7628736ef738fdbf3d9a28578c26c, 'serial_core: Fix conditional start_tx on ring buffer not empty' exposes an incorrect assumption in sunsab's start_tx method; the tx ring buffer can, in fact, be empty when restarting tx when performing flow control. Test for empty tx ring buffer when in sunsab's start_tx method. Signed-off-by: Peter Hurley --- drivers/tty/serial/sunsab.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c index 5faa8e9..b99a4ea 100644 --- a/drivers/tty/serial/sunsab.c +++ b/drivers/tty/serial/sunsab.c @@ -427,6 +427,9 @@ static void sunsab_start_tx(struct uart_port *port) struct circ_buf *xmit = &up->port.state->xmit; int i; + if (uart_circ_empty(xmit)) + return; + up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR); writeb(up->interrupt_mask1, &up->regs->w.imr1); -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/