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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4764C4332F for ; Thu, 17 Feb 2022 13:59:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241555AbiBQN71 (ORCPT ); Thu, 17 Feb 2022 08:59:27 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:57920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241518AbiBQN7X (ORCPT ); Thu, 17 Feb 2022 08:59:23 -0500 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.154.123]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9EEB72B0499; Thu, 17 Feb 2022 05:59:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1645106348; x=1676642348; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5CBNrT3wyzVzrpSF0kGVpCt0feLQUV++qdgAJ3HlDcM=; b=gC7VYVZ6huL2tNpMQ+rn3rv7NblH8S7Urid8SG2wOZ4+HtQcTE5N7AEN s3fNOc0ibM8vlGLIYr6KymAvmqgDRd4xd06L9HZz3yNaMnMgXo11IXwi/ pM5leBOw5dGu2DgNMHlMLEBk8OvvRPUL/jrwYrCjdr6cAqVnV6mR2yCCm UDpS8409RR0JqpWDN5fgVqobNwKwL97rKn83av/BgKFD3QS4hKbC829sq Ow6hyeyvy+oHwtv8KWKkSgexrqQUGkjHvW4wMeiURvx3JahTfETweAjk1 WDXbp7lqU6xr8VzdLbCMT+bOHK777xh5VukxQpRnD2QBe3mU9Cux51hwr w==; IronPort-SDR: hqV7svqrnkDUGojrzDGdn55yf2bibkn89GYGYSqPUi22iUurlBrTBnNvLPa/Xa5HTok3ypsN9M mBtfaSeTgkP4NnnLypkv1FpU+aw4AszVLmL3I3yzoEymm/wgZfpcITeFdySsG+JTr8pIg7Km+t m+TrAFcp5KcgpzyO3F4dQgCXapBlHmyR3SuQER0RaZQINIFIj8vHtPpgZs869HkLS8j2OPYtM/ 5CV7JpbqSXwcy314Yk4m7dnu5xkc3cbjTTnv2FUTcGsWiRbc4IRnR+Sr0iC7+uGTxFI4cp3lxf X+wHty6fwPvX24a4dOMQp1+2 X-IronPort-AV: E=Sophos;i="5.88,376,1635231600"; d="scan'208";a="149064270" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa2.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 17 Feb 2022 06:59:08 -0700 Received: from chn-vm-ex04.mchp-main.com (10.10.85.152) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.17; Thu, 17 Feb 2022 06:59:07 -0700 Received: from ROB-ULT-M18282.microchip.com (10.10.115.15) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server id 15.1.2375.17 via Frontend Transport; Thu, 17 Feb 2022 06:58:53 -0700 From: Eugen Hristev To: , , , CC: , , , , "Eugen Hristev" Subject: [PATCH v5 06/13] media: atmel: atmel-isc-base: use mutex to lock awb workqueue from streaming Date: Thu, 17 Feb 2022 15:56:38 +0200 Message-ID: <20220217135645.1427466-7-eugen.hristev@microchip.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220217135645.1427466-1-eugen.hristev@microchip.com> References: <20220217135645.1427466-1-eugen.hristev@microchip.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The AWB workqueue runs in a kernel thread and needs to be synchronized w.r.t. the streaming status. It is possible that streaming is stopped while the AWB workq is running. In this case it is likely that the check for vb2_start_streaming_called is done at one point in time, but the AWB computations are done later, including a call to isc_update_profile, which requires streaming to be started. Thus , isc_update_profile will fail if during this operation sequence the streaming was stopped. To solve this issue, a mutex is added, that will serialize the awb work and streaming stopping, with the mention that either streaming is stopped completely including termination of the last frame is done, and after that the AWB work can check stream status and stop; either first AWB work is completed and after that the streaming can stop correctly. The awb spin lock cannot be used since this spinlock is taken in the same context and using it in the stop streaming will result in a recursion BUG. Signed-off-by: Eugen Hristev --- drivers/media/platform/atmel/atmel-isc-base.c | 29 ++++++++++++++++--- drivers/media/platform/atmel/atmel-isc.h | 2 ++ 2 files changed, 27 insertions(+), 4 deletions(-) diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c index 74f575544e09..37c59bb4dc18 100644 --- a/drivers/media/platform/atmel/atmel-isc-base.c +++ b/drivers/media/platform/atmel/atmel-isc-base.c @@ -401,6 +401,7 @@ static void isc_stop_streaming(struct vb2_queue *vq) struct isc_buffer *buf; int ret; + mutex_lock(&isc->awb_mutex); v4l2_ctrl_activate(isc->do_wb_ctrl, false); isc->stop = true; @@ -410,6 +411,8 @@ static void isc_stop_streaming(struct vb2_queue *vq) v4l2_err(&isc->v4l2_dev, "Timeout waiting for end of the capture\n"); + mutex_unlock(&isc->awb_mutex); + /* Disable DMA interrupt */ regmap_write(isc->regmap, ISC_INTDIS, ISC_INT_DDONE); @@ -1397,10 +1400,6 @@ static void isc_awb_work(struct work_struct *w) u32 min, max; int ret; - /* streaming is not active anymore */ - if (isc->stop) - return; - if (ctrls->hist_stat != HIST_ENABLED) return; @@ -1455,7 +1454,24 @@ static void isc_awb_work(struct work_struct *w) } regmap_write(regmap, ISC_HIS_CFG + isc->offsets.his, hist_id | baysel | ISC_HIS_CFG_RAR); + + /* + * We have to make sure the streaming has not stopped meanwhile. + * ISC requires a frame to clock the internal profile update. + * To avoid issues, lock the sequence with a mutex + */ + mutex_lock(&isc->awb_mutex); + + /* streaming is not active anymore */ + if (isc->stop) { + mutex_unlock(&isc->awb_mutex); + return; + }; + isc_update_profile(isc); + + mutex_unlock(&isc->awb_mutex); + /* if awb has been disabled, we don't need to start another histogram */ if (ctrls->awb) regmap_write(regmap, ISC_CTRLEN, ISC_CTRL_HISREQ); @@ -1548,6 +1564,7 @@ static int isc_s_awb_ctrl(struct v4l2_ctrl *ctrl) */ v4l2_ctrl_activate(isc->do_wb_ctrl, false); } + mutex_unlock(&isc->awb_mutex); /* if we have autowhitebalance on, start histogram procedure */ if (ctrls->awb == ISC_WB_AUTO && @@ -1740,6 +1757,7 @@ static void isc_async_unbind(struct v4l2_async_notifier *notifier, { struct isc_device *isc = container_of(notifier->v4l2_dev, struct isc_device, v4l2_dev); + mutex_destroy(&isc->awb_mutex); cancel_work_sync(&isc->awb_work); video_unregister_device(&isc->video_dev); v4l2_ctrl_handler_free(&isc->ctrls.handler); @@ -1850,6 +1868,8 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier) isc->current_subdev = container_of(notifier, struct isc_subdev_entity, notifier); mutex_init(&isc->lock); + mutex_init(&isc->awb_mutex); + init_completion(&isc->comp); /* Initialize videobuf2 queue */ @@ -1929,6 +1949,7 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier) video_unregister_device(vdev); isc_async_complete_err: + mutex_destroy(&isc->awb_mutex); mutex_destroy(&isc->lock); return ret; } diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h index c1ca3916700e..ac8c8679dd53 100644 --- a/drivers/media/platform/atmel/atmel-isc.h +++ b/drivers/media/platform/atmel/atmel-isc.h @@ -229,6 +229,7 @@ enum isc_scaler_pads { * * @lock: lock for serializing userspace file operations * with ISC operations + * @awb_mutex: serialize access to streaming status from awb work queue * @awb_lock: lock for serializing awb work queue operations * with DMA/buffer operations * @@ -309,6 +310,7 @@ struct isc_device { struct work_struct awb_work; struct mutex lock; + struct mutex awb_mutex; spinlock_t awb_lock; struct regmap_field *pipeline[ISC_PIPE_LINE_NODE_NUM]; -- 2.25.1