From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755152AbbE0T2K (ORCPT ); Wed, 27 May 2015 15:28:10 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:42187 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753605AbbE0TBJ (ORCPT ); Wed, 27 May 2015 15:01:09 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Felipe Balbi , Luis Henriques , Kamal Mostafa Subject: [PATCH 3.13.y-ckt 10/95] usb: musb: core: fix TX/RX endpoint order Date: Wed, 27 May 2015 11:59:18 -0700 Message-Id: <1432753243-16151-11-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1432753243-16151-1-git-send-email-kamal@canonical.com> References: <1432753243-16151-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11-ckt21 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Felipe Balbi commit e3c93e1a3f35be4cf1493d3ccfb0c6d9209e4922 upstream. As per Mentor Graphics' documentation, we should always handle TX endpoints before RX endpoints. This patch fixes that error while also updating some hard-to-read comments which were scattered around musb_interrupt(). This patch should be backported as far back as possible since this error has been in the driver since it's conception. Signed-off-by: Felipe Balbi [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques Signed-off-by: Kamal Mostafa --- drivers/usb/musb/musb_core.c | 44 ++++++++++++++++++++++++++------------------ 1 file changed, 26 insertions(+), 18 deletions(-) diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c index b29331e..7dc2019 100644 --- a/drivers/usb/musb/musb_core.c +++ b/drivers/usb/musb/musb_core.c @@ -1514,16 +1514,30 @@ irqreturn_t musb_interrupt(struct musb *musb) (devctl & MUSB_DEVCTL_HM) ? "host" : "peripheral", musb->int_usb, musb->int_tx, musb->int_rx); - /* the core can interrupt us for multiple reasons; docs have - * a generic interrupt flowchart to follow + /** + * According to Mentor Graphics' documentation, flowchart on page 98, + * IRQ should be handled as follows: + * + * . Resume IRQ + * . Session Request IRQ + * . VBUS Error IRQ + * . Suspend IRQ + * . Connect IRQ + * . Disconnect IRQ + * . Reset/Babble IRQ + * . SOF IRQ (we're not using this one) + * . Endpoint 0 IRQ + * . TX Endpoints + * . RX Endpoints + * + * We will be following that flowchart in order to avoid any problems + * that might arise with internal Finite State Machine. */ + if (musb->int_usb) retval |= musb_stage0_irq(musb, musb->int_usb, devctl); - /* "stage 1" is handling endpoint irqs */ - - /* handle endpoint 0 first */ if (musb->int_tx & 1) { if (devctl & MUSB_DEVCTL_HM) retval |= musb_h_ep0_irq(musb); @@ -1531,37 +1545,31 @@ irqreturn_t musb_interrupt(struct musb *musb) retval |= musb_g_ep0_irq(musb); } - /* RX on endpoints 1-15 */ - reg = musb->int_rx >> 1; + reg = musb->int_tx >> 1; ep_num = 1; while (reg) { if (reg & 1) { - /* musb_ep_select(musb->mregs, ep_num); */ - /* REVISIT just retval = ep->rx_irq(...) */ retval = IRQ_HANDLED; if (devctl & MUSB_DEVCTL_HM) - musb_host_rx(musb, ep_num); + musb_host_tx(musb, ep_num); else - musb_g_rx(musb, ep_num); + musb_g_tx(musb, ep_num); } - reg >>= 1; ep_num++; } - /* TX on endpoints 1-15 */ - reg = musb->int_tx >> 1; + reg = musb->int_rx >> 1; ep_num = 1; while (reg) { if (reg & 1) { - /* musb_ep_select(musb->mregs, ep_num); */ - /* REVISIT just retval |= ep->tx_irq(...) */ retval = IRQ_HANDLED; if (devctl & MUSB_DEVCTL_HM) - musb_host_tx(musb, ep_num); + musb_host_rx(musb, ep_num); else - musb_g_tx(musb, ep_num); + musb_g_rx(musb, ep_num); } + reg >>= 1; ep_num++; } -- 1.9.1