[{"id":39005,"web_url":"https://patchwork.libcamera.org/comment/39005/","msgid":"<178059838285.1119811.5500173666150259611@ping.linuxembedded.co.uk>","date":"2026-06-04T18:39:42","subject":"Re: [RFC PATCH v3 04/17] libcamera: software_isp: Handle\n\tqueueBuffers failure","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Milan Zamazal (2026-06-04 10:50:47)\n> Currently, if a call to queueBuffers fails, the error is ignored. Which\n> means buffers are not returned back, as would be the case at the end of\n> normal processing. Let's cancel the request, which also returns the\n> output buffers. The input buffer is returned as well in case of raw\n> streams and must be returned manually in case of non-raw streams.\n> \n> Signed-off-by: Milan Zamazal \n> ---\n> src/libcamera/pipeline/simple/simple.cpp | 28 +++++++++++++++++++-----\n> 1 file changed, 23 insertions(+), 5 deletions(-)\n> \n> diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp\n> index c6fe12d65..93899699e 100644\n> --- a/src/libcamera/pipeline/simple/simple.cpp\n> +++ b/src/libcamera/pipeline/simple/simple.cpp\n> @@ -955,16 +955,34 @@ void SimpleCameraData::imageBufferReady(FrameBuffer *buffer)\n> return;\n> }\n> \n> - if (converter_)\n> - converter_->queueBuffers(buffer, conversionQueue_.front().outputs);\n> - else\n> + int ret;\n> + if (converter_) {\n> + ret = converter_->queueBuffers(buffer, conversionQueue_.front().outputs);\n> + } else {\n> /*\n> * request->sequence() cannot be retrieved from `buffer' inside\n> * queueBuffers because unique_ptr's make buffer->request() invalid\n> * already here.\n> */\n> - swIsp_->queueBuffers(request->sequence(), buffer,\n> - conversionQueue_.front().outputs);\n> + ret = swIsp_->queueBuffers(request->sequence(), buffer,\n> + conversionQueue_.front().outputs);\n> + }\n> +\n> + if (ret < 0) {\n> + LOG(SimplePipeline, Error)\n> + << \"Failed to queue buffers for conversion: \"\n> + << strerror(-ret);\n> + /*\n> + * The buffers were rejected before starting any processing, so the\n> + * output buffers will not be returned via the normal done\n> + * signals. Cancel the request; this handles the output buffers and\n> + * also the input buffer if it's a raw stream buffer. For non-raw\n> + * streams, return the input buffer to the video device manually.\n> + */\n\nThis feels a bit awkward, I wonder if we could do better here (globally?\nnot just in simple I think unless this is due to something specific to\nsimple?)\n\n\n> + pipe->cancelRequest(request);\n\nIs there any difference calling request->_d()->cancel()?\n\nAha, I see, we have to call cancel on the pipeline handler to complete\nit back to the application.\n\nI'm curious why this is only called by simple and virtual... \n\nSomething seems fishy here ... ? \n\n\n> + if (!rawStream_)\n> + video_->queueBuffer(buffer);\n> + }\n> \n> conversionQueue_.pop();\n> return;\n> -- \n> 2.54.0\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id D6CCCC324C\n\tfor ;\n\tThu, 4 Jun 2026 18:39:47 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id E39576344D;\n\tThu, 4 Jun 2026 20:39:46 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 00CAD62DC4\n\tfor ;\n\tThu, 4 Jun 2026 20:39:45 +0200 (CEST)","from monstersaurus.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 0503A13D7;\n\tThu, 4 Jun 2026 20:39:20 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"AFntE1OB\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1780598361;\n\tbh=lgEJ1gdUjDFKN01d22D+mcxO+9ygdQqTmwnBA9QRTPA=;\n\th=In-Reply-To:References:Subject:From:Cc:To:Date:From;\n\tb=AFntE1OBcuYuji0a9oNIGM/FmWOBESkYzysBQLMcrt2H3fSsHo64WpL2ELDQy5S4F\n\tRwmaRLNVKuqXpiCqTsy2SYvxZhh9kstyMkeA1IEaZgqI+P3NEBuETMlWMDFqmvC61s\n\tMvN3zCzQNUUzqsmEAJ5gcVNFnjV+SRFDdA5kg3OE=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20260604095105.68798-6-mzamazal@redhat.com>","References":"<20260604095105.68798-1-mzamazal@redhat.com>\n\t<20260604095105.68798-6-mzamazal@redhat.com>","Subject":"Re: [RFC PATCH v3 04/17] libcamera: software_isp: Handle\n\tqueueBuffers failure","From":"Kieran Bingham ","Cc":"Milan Zamazal , =?utf-8?b?QmFybmFiw6FzIFDFkWN6?=\n\t=?utf-8?q?e?= ,\n\tjohannes.goede@oss.qualcomm.com","To":"Milan Zamazal , libcamera-devel@lists.libcamera.org","Date":"Thu, 04 Jun 2026 19:39:42 +0100","Message-ID":"<178059838285.1119811.5500173666150259611@ping.linuxembedded.co.uk>","User-Agent":"alot/0.9.1","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":39011,"web_url":"https://patchwork.libcamera.org/comment/39011/","msgid":"<85se6xxffg.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","date":"2026-06-08T14:41:39","subject":"Re: [RFC PATCH v3 04/17] libcamera: software_isp: Handle\n\tqueueBuffers failure","submitter":{"id":177,"url":"https://patchwork.libcamera.org/api/people/177/","name":"Milan Zamazal","email":"mzamazal@redhat.com"},"content":"Hi Kieran,\n\nthank you for review.\n\nKieran Bingham writes:\n\n> Quoting Milan Zamazal (2026-06-04 10:50:47)\n>> Currently, if a call to queueBuffers fails, the error is ignored. Which\n>> means buffers are not returned back, as would be the case at the end of\n>\n>> normal processing. Let's cancel the request, which also returns the\n>> output buffers. The input buffer is returned as well in case of raw\n>> streams and must be returned manually in case of non-raw streams.\n>> \n>> Signed-off-by: Milan Zamazal \n>> ---\n>> src/libcamera/pipeline/simple/simple.cpp | 28 +++++++++++++++++++-----\n>> 1 file changed, 23 insertions(+), 5 deletions(-)\n>> \n>> diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp\n>> index c6fe12d65..93899699e 100644\n>> --- a/src/libcamera/pipeline/simple/simple.cpp\n>> +++ b/src/libcamera/pipeline/simple/simple.cpp\n>> @@ -955,16 +955,34 @@ void SimpleCameraData::imageBufferReady(FrameBuffer *buffer)\n>> return;\n>> }\n>> \n>> - if (converter_)\n>> - converter_->queueBuffers(buffer, conversionQueue_.front().outputs);\n>> - else\n>> + int ret;\n>> + if (converter_) {\n>> + ret = converter_->queueBuffers(buffer, conversionQueue_.front().outputs);\n>> + } else {\n>> /*\n>> * request->sequence() cannot be retrieved from `buffer' inside\n>> * queueBuffers because unique_ptr's make buffer->request() invalid\n>> * already here.\n>> */\n>> - swIsp_->queueBuffers(request->sequence(), buffer,\n>> - conversionQueue_.front().outputs);\n>> + ret = swIsp_->queueBuffers(request->sequence(), buffer,\n>> + conversionQueue_.front().outputs);\n>> + }\n>> +\n>> + if (ret < 0) {\n>> + LOG(SimplePipeline, Error)\n>> + << \"Failed to queue buffers for conversion: \"\n>> + << strerror(-ret);\n>> + /*\n>> + * The buffers were rejected before starting any processing, so the\n>> + * output buffers will not be returned via the normal done\n>> + * signals. Cancel the request; this handles the output buffers and\n>> + * also the input buffer if it's a raw stream buffer. For non-raw\n>> + * streams, return the input buffer to the video device manually.\n>> + */\n>\n> This feels a bit awkward, \n\nYes.\n\n> I wonder if we could do better here (globally? not just in simple I\n> think unless this is due to something specific to simple?)\n\nA tricky question, I'm afraid I don't have an answer.\n\n>> + pipe->cancelRequest(request);\n>\n> Is there any difference calling request->_d()->cancel()?\n> \n> Aha, I see, we have to call cancel on the pipeline handler to complete\n> it back to the application.\n>\n> I'm curious why this is only called by simple and virtual... \n>\n> Something seems fishy here ... ? \n\nAnother tricky question...\n\n>> + if (!rawStream_)\n>> + video_->queueBuffer(buffer);\n>> + }\n>> \n>> conversionQueue_.pop();\n>> return;\n>> -- \n>> 2.54.0\n>>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 08C3FC328C\n\tfor ;\n\tMon, 8 Jun 2026 14:41:49 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 1E0C061E77;\n\tMon, 8 Jun 2026 16:41:48 +0200 (CEST)","from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.129.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 3664561E74\n\tfor ;\n\tMon, 8 Jun 2026 16:41:47 +0200 (CEST)","from mail-wm1-f70.google.com (mail-wm1-f70.google.com\n\t[209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS\n\t(version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id\n\tus-mta-225-_37walR-PtuX8yjD4IIU9A-1; Mon, 08 Jun 2026 10:41:42 -0400","by mail-wm1-f70.google.com with SMTP id\n\t5b1f17b1804b1-490b37e1f48so36780245e9.0\n\tfor ;\n\tMon, 08 Jun 2026 07:41:42 -0700 (PDT)","from mzamazal-thinkpadp1gen7.tpbc.csb\n\t(ip-77-48-47-4.net.vodafone.cz. 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