From patchwork Wed Jan 16 00:01:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Elder X-Patchwork-Id: 10765257 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CF3A914E5 for ; Wed, 16 Jan 2019 00:02:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B99372E101 for ; Wed, 16 Jan 2019 00:02:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A85502E17C; Wed, 16 Jan 2019 00:02:08 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 91C3C2E17C for ; Wed, 16 Jan 2019 00:02:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728953AbfAPACB (ORCPT ); Tue, 15 Jan 2019 19:02:01 -0500 Received: from perceval.ideasonboard.com ([213.167.242.64]:49448 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728728AbfAPACB (ORCPT ); Tue, 15 Jan 2019 19:02:01 -0500 Received: from localhost.localdomain (unknown [96.44.9.117]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id F25CE530; Wed, 16 Jan 2019 01:01:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1547596919; bh=sg4t8JOjyLOwJH2mu0Q5VtvgoxoNuNHPOUq7xguwWug=; h=From:To:Cc:Subject:Date:From; b=JyK6avjqQHpHBBcI46E/FkKs3dFHAGs8rgAkA/O51mfk+MU1w6bFjeMa5ALs4D5Sc vhTiOCVQK3MchOIw5rpGktlTgTwjd9dNe6yyc1rYRyuffEn8fE5OQrcaaxmrnNtJf1 9uLwPPbPuSV5+3BUEAiRP280z79xnTWcJvQxnVfA= From: Paul Elder To: laurent.pinchart@ideasonboard.com, kieran.bingham@ideasonboard.com, b-liu@ti.com Cc: Paul Elder , drinkcat@chromium.org, balbi@kernel.org, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] usb: gadget: musb: fix short isoc packets with inventra dma Date: Tue, 15 Jan 2019 19:01:45 -0500 Message-Id: <20190116000145.5816-1-paul.elder@ideasonboard.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Handling short packets (length < max packet size) in the Inventra DMA engine in the MUSB driver causes the MUSB DMA controller to hang. An example of a problem that is caused by this problem is when streaming video out of a UVC gadget, only the first video frame is transferred. For short packets (mode-0 or mode-1 DMA), MUSB_TXCSR_TXPKTRDY must be set manually by the driver. This was previously done in musb_g_tx (musb_gadget.c), but incorrectly (all csr flags were cleared, and only MUSB_TXCSR_MODE and MUSB_TXCSR_TXPKTRDY were set). Fixing that problem allows some requests to be transferred correctly, but multiple requests were often put together in one USB packet, and caused problems if the packet size was not a multiple of 4. Instead, set MUSB_TXCSR_TXPKTRDY in dma_controller_irq (musbhsdma.c), just like host mode transfers. This topic was originally tackled by Nicolas Boichat [0] [1] and is discussed further at [2] as part of his GSoC project [3]. [0] https://groups.google.com/forum/?hl=en#!topic/beagleboard-gsoc/k8Azwfp75CU [1] https://gitorious.org/beagleboard-usbsniffer/beagleboard-usbsniffer-kernel/commit/b0be3b6cc195ba732189b04f1d43ec843c3e54c9?p=beagleboard-usbsniffer:beagleboard-usbsniffer-kernel.git;a=patch;h=b0be3b6cc195ba732189b04f1d43ec843c3e54c9 [2] http://beagleboard-usbsniffer.blogspot.com/2010/07/musb-isochronous-transfers-fixed.html [3] http://elinux.org/BeagleBoard/GSoC/USBSniffer Signed-off-by: Paul Elder --- Changes in v3: - remove unnecessary chunk for sending short packet Changes in v2: - no more flushing FIFO - greatly simplified short packet if guard in musb_g_tx, and removed unnecessary variables - minor indentation and wording changes drivers/usb/musb/musb_gadget.c | 13 +------------ drivers/usb/musb/musbhsdma.c | 21 +++++++++++---------- 2 files changed, 12 insertions(+), 22 deletions(-) diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c index eae8b1b1b45b..ffe462a657b1 100644 --- a/drivers/usb/musb/musb_gadget.c +++ b/drivers/usb/musb/musb_gadget.c @@ -452,13 +452,10 @@ void musb_g_tx(struct musb *musb, u8 epnum) } if (request) { - u8 is_dma = 0; - bool short_packet = false; trace_musb_req_tx(req); if (dma && (csr & MUSB_TXCSR_DMAENAB)) { - is_dma = 1; csr |= MUSB_TXCSR_P_WZC_BITS; csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET); @@ -476,16 +473,8 @@ void musb_g_tx(struct musb *musb, u8 epnum) */ if ((request->zero && request->length) && (request->length % musb_ep->packet_sz == 0) - && (request->actual == request->length)) - short_packet = true; + && (request->actual == request->length)) { - if ((musb_dma_inventra(musb) || musb_dma_ux500(musb)) && - (is_dma && (!dma->desired_mode || - (request->actual & - (musb_ep->packet_sz - 1))))) - short_packet = true; - - if (short_packet) { /* * On DMA completion, FIFO may not be * available yet... diff --git a/drivers/usb/musb/musbhsdma.c b/drivers/usb/musb/musbhsdma.c index a688f7f87829..5fc6825745f2 100644 --- a/drivers/usb/musb/musbhsdma.c +++ b/drivers/usb/musb/musbhsdma.c @@ -346,12 +346,10 @@ static irqreturn_t dma_controller_irq(int irq, void *private_data) channel->status = MUSB_DMA_STATUS_FREE; /* completed */ - if ((devctl & MUSB_DEVCTL_HM) - && (musb_channel->transmit) - && ((channel->desired_mode == 0) - || (channel->actual_len & - (musb_channel->max_packet_sz - 1))) - ) { + if (musb_channel->transmit && + (!channel->desired_mode || + (channel->actual_len % + musb_channel->max_packet_sz))) { u8 epnum = musb_channel->epnum; int offset = musb->io.ep_offset(epnum, MUSB_TXCSR); @@ -363,11 +361,14 @@ static irqreturn_t dma_controller_irq(int irq, void *private_data) */ musb_ep_select(mbase, epnum); txcsr = musb_readw(mbase, offset); - txcsr &= ~(MUSB_TXCSR_DMAENAB + if (channel->desired_mode == 1) { + txcsr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_AUTOSET); - musb_writew(mbase, offset, txcsr); - /* Send out the packet */ - txcsr &= ~MUSB_TXCSR_DMAMODE; + musb_writew(mbase, offset, txcsr); + /* Send out the packet */ + txcsr &= ~MUSB_TXCSR_DMAMODE; + txcsr |= MUSB_TXCSR_DMAENAB; + } txcsr |= MUSB_TXCSR_TXPKTRDY; musb_writew(mbase, offset, txcsr); }