From patchwork Sun Oct 3 02:36:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott K Logan X-Patchwork-Id: 77413 Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1mWrN4-002Foa-KW; Sun, 03 Oct 2021 02:36:59 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229588AbhJCCim (ORCPT + 1 other); Sat, 2 Oct 2021 22:38:42 -0400 Received: from wrqvnhvw.outbound-mail.sendgrid.net ([149.72.32.137]:8308 "EHLO wrqvnhvw.outbound-mail.sendgrid.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229534AbhJCCil (ORCPT ); Sat, 2 Oct 2021 22:38:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cottsay.net; h=from:subject:mime-version:to:cc:content-transfer-encoding: content-type; s=s1; bh=It6jebDl3nuns7IOICpyjNP6KBken6kJglWUNWJd05c=; b=Fjen4CAFgDAzU0TeZGdLzoV3XSdhunLat8sDYUmUqcaO9HkhUR7pGyUbaVTmh0cBM/BB w/2F9dGCGYMpI/HNNx3Je+bUfDHVZHuw8opG/j/Z5cqOzm1T9oPTeWVENi1pVYWY6fgzJh HV4Pknj2tqQFWOusOdlGEYwo6mt9Hg13/9kRSut0apxvlqV1/lCYWFgDJimd/mSmhh/bpB Wry5CAQFl/52VAQBNElBrCrUUgHqR7SS1DmoagDGX6dOhDl806jRcSkejaBylbg6+WjVFW vDnTxKS5v0MfP/MNzwLTI075Vr4oItnkOabwrfdiO4qwnr+x02nl6zJQ1XC+g5TA== Received: by filterdrecv-7bc86b958d-gt6pz with SMTP id filterdrecv-7bc86b958d-gt6pz-1-61591746-15 2021-10-03 02:36:54.713588009 +0000 UTC m=+2693817.404992980 Received: from cottsay-server.delphi.cottsay.net (unknown) by geopod-ismtpd-2-0 (SG) with ESMTP id dP__pBiOTCa1nC87CW5o3Q Sun, 03 Oct 2021 02:36:54.518 +0000 (UTC) Received: from cottsay-lenovo.delphi.cottsay.net (cottsay-lenovo.delphi.cottsay.net [172.16.8.31]) by cottsay-server.delphi.cottsay.net (Postfix) with ESMTPSA id ED2B53C0436; Sat, 2 Oct 2021 19:36:53 -0700 (PDT) From: Scott K Logan Subject: [PATCH 0/1] media: uvcvideo: Add quirk for exponential exposure Date: Sun, 03 Oct 2021 02:36:54 +0000 (UTC) Message-Id: <20211003023554.885815-1-logans@cottsay.net> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-SG-EID: v4Qh49l2kwszIc8ZaCpP76AQaq/9O0v3P/mBhAlry1T/zVhHBJ8w+hDrqxBvdAKU3ehgFPlGwC1hR8j2nf+OmGtuprMcj/Tu7H5rEyJ7p4WUeAcPe9mMZdpr8ZVq11J8Ws8QnGKDoQSgj66lfmXaXkZK7g6E5AlF8LYP3u4Xaacawm+ltaPNhBRzkhu1m93oL6VMMm0T4Yz6j/ngMVY3A2eTb0gt/1oge7IjzkBB6nJYbeHp/3UiwnDsOZtNw9jn To: Laurent Pinchart , subscribers-only , linux-media@vger.kernel.org Cc: Scott K Logan X-Entity-ID: 4JzoG0JXdcXknftrbeCa4w== Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -4.8 (----) X-LSpam-Report: No, score=-4.8 required=5.0 tests=BAYES_00=-1.9,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,DKIM_VALID_AU=-0.1,HEADER_FROM_DIFFERENT_DOMAINS=0.5,MAILING_LIST_MULTI=-1,RCVD_IN_DNSWL_MED=-2.3,UNPARSEABLE_RELAY=0.001 autolearn=ham autolearn_force=no Ever since I started using them, I've noticed that the absolute exposure control for the LifeCam webcam hasn't functioned properly. After some poking around, I managed to charactarize the behavior. To summarize, only values which follow an exponential pattern appear to result in the intended change to the webcam's image. Ideally this quirky behavior could be handled with an extension unit, but I'm not sure this behavior can be implemented there. I tested this patch with the two LifeCam webcams I have on hand. Scott K Logan (1): media: uvcvideo: Add quirk for exponential exposure drivers/media/usb/uvc/uvc_ctrl.c | 41 ++++++++++++++++++++++++++++++ drivers/media/usb/uvc/uvc_driver.c | 18 +++++++++++++ drivers/media/usb/uvc/uvcvideo.h | 1 + 3 files changed, 60 insertions(+)