From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: Can't Unload ALSA Driver Without Disconnecting the Device Date: Fri, 12 Jun 2015 08:41:26 +0200 Message-ID: References: Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id 855A1266700 for ; Fri, 12 Jun 2015 08:41:26 +0200 (CEST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Azizul Hakim Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org At Fri, 12 Jun 2015 02:28:16 -0400, Azizul Hakim wrote: > > Hi, > > I've been developing a sound card driver for a USB device using ALSA. My > driver is almost working but I've got one small issue. If I try to unload > the driver module using "rmmod" command when the device is still connected > to the USB port, it says "Module is in use" even though I'm not playing any > sound files or anything. > > > If I try to execute the "lsmod" command I see that it is saying the usage > count of my driver to be 1, but it doesn't say anything about who is using > it. Once I disconnect the device from the USB port, I can easily unload the > module. > > > So it seems to me it won't be possible to unload a sound card driver if the > card is attached in the computer. Is my assumption correct? If not, what > might be some key points to solve the issue? Check "fuser -v /dev/snd/*" as root. Something (e.g. a mixer application or sound backend) must be accessing the device. Takashi