From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754362AbdBET0m (ORCPT + 2 others); Sun, 5 Feb 2017 14:26:42 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:28294 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753570AbdBET0j (ORCPT ); Sun, 5 Feb 2017 14:26:39 -0500 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Yoshihiro Shimoda , Felipe Balbi , Willy Tarreau Subject: [PATCH 3.10 114/319] usb: renesas_usbhs: fix clearing the {BRDY,BEMP}STS condition Date: Sun, 5 Feb 2017 20:18:56 +0100 Message-Id: <1486322541-8206-15-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1486322541-8206-1-git-send-email-w@1wt.eu> References: <1486322541-8206-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Yoshihiro Shimoda commit 519d8bd4b5d3d82c413eac5bb42b106bb4b9ec15 upstream. The previous driver is possible to stop the transfer wrongly. For example: 1) An interrupt happens, but not BRDY interruption. 2) Read INTSTS0. And than state->intsts0 is not set to BRDY. 3) BRDY is set to 1 here. 4) Read BRDYSTS. 5) Clear the BRDYSTS. And then. the BRDY is cleared wrongly. Remarks: - The INTSTS0.BRDY is read only. - If any bits of BRDYSTS are set to 1, the BRDY is set to 1. - If BRDYSTS is 0, the BRDY is set to 0. So, this patch adds condition to avoid such situation. (And about NRDYSTS, this is not used for now. But, avoiding any side effects, this patch doesn't touch it.) Fixes: d5c6a1e024dd ("usb: renesas_usbhs: fixup interrupt status clear method") Signed-off-by: Yoshihiro Shimoda Signed-off-by: Felipe Balbi Signed-off-by: Willy Tarreau --- drivers/usb/renesas_usbhs/mod.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/usb/renesas_usbhs/mod.c b/drivers/usb/renesas_usbhs/mod.c index 6a030b9..254194d 100644 --- a/drivers/usb/renesas_usbhs/mod.c +++ b/drivers/usb/renesas_usbhs/mod.c @@ -272,9 +272,16 @@ static irqreturn_t usbhs_interrupt(int irq, void *data) usbhs_write(priv, INTSTS0, ~irq_state.intsts0 & INTSTS0_MAGIC); usbhs_write(priv, INTSTS1, ~irq_state.intsts1 & INTSTS1_MAGIC); - usbhs_write(priv, BRDYSTS, ~irq_state.brdysts); + /* + * The driver should not clear the xxxSTS after the line of + * "call irq callback functions" because each "if" statement is + * possible to call the callback function for avoiding any side effects. + */ + if (irq_state.intsts0 & BRDY) + usbhs_write(priv, BRDYSTS, ~irq_state.brdysts); usbhs_write(priv, NRDYSTS, ~irq_state.nrdysts); - usbhs_write(priv, BEMPSTS, ~irq_state.bempsts); + if (irq_state.intsts0 & BEMP) + usbhs_write(priv, BEMPSTS, ~irq_state.bempsts); /* * call irq callback functions -- 2.8.0.rc2.1.gbe9624a