From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.abilis.ch ([195.70.19.74]:45763 "EHLO mail.abilis.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751549AbaEZOnj convert rfc822-to-8bit (ORCPT ); Mon, 26 May 2014 10:43:39 -0400 Date: Mon, 26 May 2014 16:17:48 +0200 (CEST) From: Romain Baeriswyl To: Mauro Carvalho Chehab Cc: Christian Ruppert , Ole Ernst , linux-media@vger.kernel.org Message-ID: <1586019348.6279.1401113868322.JavaMail.root@abilis.com> In-Reply-To: <832879218.6141.1401112530064.JavaMail.root@abilis.com> Subject: Linux DVB frontend issue MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-media-owner@vger.kernel.org List-ID: Dear Mauro, We are using the Linux DVB frontend module on our platform and we are facing an issue when having concurrent calls with FE_SET_FRONTEND and FE_GET_FRONTEND ioctl. Issue is that both ioctls are using the same dtv_property_cache buffer. If a FE_SET_FRONTEND ioctl is interrupted by a FE_GET_FRONTEND then the dtv_property_cache is overwritten with the result of the FE_GET_FRONTEND. When the FE_SET_FRONTEND operation resumes, the dtv_property_cache may not be accurate anymore. Did you already face this issue? Up to now I tried, without success, to think on a fix that does not impact too much the existing code. One solution could be to have one cache for reading properties and one other cache for writing properties, but this will impact all the drivers below the DVB frontend. Do you see another less impacting solution? Best regards, Romain Baeriswyl Abilis Systems 3, chemin Pré Fleuri CH-1228 Plan-Les-Ouates Geneva