From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 923D8C43387 for ; Fri, 18 Jan 2019 10:24:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 69CD020823 for ; Fri, 18 Jan 2019 10:24:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726864AbfARKYL (ORCPT ); Fri, 18 Jan 2019 05:24:11 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:39257 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725983AbfARKYL (ORCPT ); Fri, 18 Jan 2019 05:24:11 -0500 Received: from lupine.hi.pengutronix.de ([2001:67c:670:100:3ad5:47ff:feaf:1a17] helo=lupine) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1gkRJl-00021k-Nj; Fri, 18 Jan 2019 11:24:05 +0100 Message-ID: <1547807043.3375.3.camel@pengutronix.de> Subject: Re: [PATCH v2 1/2] media: imx: csi: Disable CSI immediately after last EOF From: Philipp Zabel To: Steve Longerbeam , linux-media@vger.kernel.org Cc: stable@vger.kernel.org, Mauro Carvalho Chehab , Greg Kroah-Hartman , "open list:STAGING SUBSYSTEM" , open list Date: Fri, 18 Jan 2019 11:24:03 +0100 In-Reply-To: <20190117204912.28456-2-slongerbeam@gmail.com> References: <20190117204912.28456-1-slongerbeam@gmail.com> <20190117204912.28456-2-slongerbeam@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:100:3ad5:47ff:feaf:1a17 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2019-01-17 at 12:49 -0800, Steve Longerbeam wrote: > Disable the CSI immediately after receiving the last EOF before stream > off (and thus before disabling the IDMA channel). > > This fixes a complete system hard lockup on the SabreAuto when streaming > from the ADV7180, by repeatedly sending a stream off immediately followed > by stream on: > > while true; do v4l2-ctl -d4 --stream-mmap --stream-count=3; done > > Eventually this either causes the system lockup or EOF timeouts at all > subsequent stream on, until a system reset. > > The lockup occurs when disabling the IDMA channel at stream off. Disabling > the CSI before disabling the IDMA channel appears to be a reliable fix for > the hard lockup. > > Fixes: 4a34ec8e470cb ("[media] media: imx: Add CSI subdev driver") > > Reported-by: Gaël PORTAY > Signed-off-by: Steve Longerbeam > Cc: stable@vger.kernel.org > --- > Changes in v2: > - restore an empty line > - Add Fixes: and Cc: stable > --- > drivers/staging/media/imx/imx-media-csi.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c > index e18f58f56dfb..e0f6f88e2e70 100644 > --- a/drivers/staging/media/imx/imx-media-csi.c > +++ b/drivers/staging/media/imx/imx-media-csi.c > @@ -681,6 +681,8 @@ static void csi_idmac_stop(struct csi_priv *priv) > if (ret == 0) > v4l2_warn(&priv->sd, "wait last EOF timeout\n"); > > + ipu_csi_disable(priv->csi); > + Can you add a short comment why this call is here? Since now csi_idmac_stop is kind of a misnomer and symmetry with csi(_idmac)_start is broken, I think this is a bit un-obvious. Also note that now the error path of csi_start() will now call ipu_csi_disable() while the CSI is disabled. This happens to work because that just calls ipu_module_disable(), which is not refcounted. > devm_free_irq(priv->dev, priv->eof_irq, priv); > devm_free_irq(priv->dev, priv->nfb4eof_irq, priv); > > @@ -793,9 +795,9 @@ static void csi_stop(struct csi_priv *priv) > /* stop the frame interval monitor */ > if (priv->fim) > imx_media_fim_set_stream(priv->fim, NULL, false); > + } else { > + ipu_csi_disable(priv->csi); > } > - > - ipu_csi_disable(priv->csi); Reviewed-by: Philipp Zabel regards Philipp