From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Kennedy Subject: Re: Ejecting/Powering off/ -> Turn off the device lamp. Date: Mon, 22 May 2006 11:50:10 -0500 Message-ID: <4471EBC2.9000607@techmoninc.com> References: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------070509090207020200060308" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: linux-pm@lists.osdl.org List-Id: linux-pm@vger.kernel.org This is a multi-part message in MIME format. --------------070509090207020200060308 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Alan Stern wrote: > On Mon, 22 May 2006, Andy Kennedy wrote: > > >> All, >> >> I have done an extensive search on this issue and cannot find the answer >> to my specific question. Whereas I understand that an individual device >> on a USB host (on board) cannot be "powered off" nor "ejected" I wonder >> if the device can be sent a command from userspace to turn off it's LED >> indicator lamp. Most of the devices that I have seen, when the device >> is no longer in use, goes into a blink cycle. >> >> Is there a way to signal the device to stop the cycle and actually power >> off the LED? >> > > It's hard to answer that question without knowing what kind of device > you're talking about. Some USB devices (like hubs) can be told to turn > off their indicators; most cannot. > > Alan Stern > Very sorry. . . I did leave out the most important part: I am working with various flash disks / USB mass storage devices. I am working with an embedded system that will have no user interaction save the USB port. The unit will recognize the mass storage device via the hotplug scripts, then execute a series of commands. . . after which the device will be unmounted and then could be removed. That is the purpose for wanting to extinguish the lamp. It would be hard to explain to a lay person to "Watch the little light. It should blink very fast for a few seconds/minutes then blink slow for a few seconds, then fast again. . . then you can remove it." and expect them to comprehend the meaning of the "little blinking light." I have TTLs on the embedded system; I may just have to use those. Andy Kennedy --------------070509090207020200060308 Content-Type: text/x-vcard; charset=utf-8; name="akennedy.vcf" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="akennedy.vcf" begin:vcard fn:Andy Kennedy n:;Andy Kennedy org:TechMon Research Inc. adr;dom:;;2221 Dianne Drive;Birmingham;AL;35235 email;internet:akennedy@techmoninc.com title:Sr. Software Engineer tel;work:(205) 854-9895 tel;cell:(256) 453-1814 version:2.1 end:vcard --------------070509090207020200060308 Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline --------------070509090207020200060308--