Re: [gentoo-user] headphone does not work in windows After logging to linux

[Mick]

On Friday 21 Nov 2014 15:24:43 Alan McKinnon wrote:
> On 21/11/2014 17:08, behrouz khosravi wrote:
> > On Nov 21, 2014 6:23 PM, "Matti Nykyri" <matti.nykyri@×××.fi
> >
> > <mailto:matti.nykyri@×××.fi>> wrote:
> >> On Nov 21, 2014, at 16:15, behrouz khosravi <bz.khosravi@×××××.com
> >
> > <mailto:bz.khosravi@×××××.com>> wrote:
> >>> > Do you reboot in the between or are you running somekind of virtual
> >
> > machine? Usb headphones or what? What sound driver? I've had problems
> > with NIC between reboots. They were cleared by removing power cord for
> > multiple minutes while rebooting. I got rid of the problem when i
> > updated NIC's driver (bug in driver).
> >
> >>> No. It happen every time I boot into linux. Gentoo or Arch.
> >>> removing power helps but is annoying.
> >>> its not usb, but I dont know what is called! the ordinary type!
> >>> Its a realtek chip .
> >>> The bug that you mentioned is related to linux driver or windows
> >>> driver?
> >>
> >> I have realtek R6168/6111/6169 NIC. It works in Linux with realtek's
> >
> > driver not with the one included in kernel. Windows fails to initialize
> > the NIC properly when I reboot from linux to windows. When NIC is reset
> > by recycling power windows will be able to initialize it. Downgrading
> > windows (7 64bit) dirver to an ancient one fixed the problem. The
> > up-to-date realtek driver didn't work correctly.
> >
> >> lspci -v
> >>
> >> You can check what driver kernel uses for you audio. Also the bug can
> >
> > be in alsa. The ways of alsa quite complicated... You are using alsa
> > right? What error message does alsa give when you try to play audio?
> > Well I have no problem with it in linux. It always works in linux but I
> > think there is a problem with alsa or some other linux related part.
> > Because I have enabled the after post sound in bios. When I power in on
> > the headphone work. Then I login to linux and when I reboot to login to
> > windows, the bios post sound does not come from headphone.
> > It seems something is wrong in the linux part!
>
> This kind of thing is quite common actually, more so in days gone past.
>
> Speaking conceptually, what happens is something like this:
>
> Consider a driver for a hardware on any OS. That driver knows how it
> shuts down the hardware. It expects the hardware to be in the same state
> (registers, sleep state, etc) when powered back up; if so then all is
> good. There are supposed to be standards for these things and drivers
> are supposed to obey them to avoid these problems when booting other
> OSes (or even upgrading a driver that needs a reboot).
>
> One of your drivers (Windows or Linux) or the hardware itself is not
> obeying the standard, so Windows doesn't find the hardware in the state
> it expects and doesn't properly initialize the hardware. There are 3
> ways this can go wrong:
>
> 1. The Linux driver is buggy (not 100% per spec) and doesn't shut
> down/power up the device properly.
> 2. Same with the Windows driver.
> 3. The hardware might not be per standard (the Windows driver will have
> been coded to work around it if this is the case).
>
> Usually, the Linux driver is coded per spec. Hardware often doesn't do
> what the spec says and Windows drivers are often shocking. It's not
> always true, but I find it's a good assumption to start from.
>
> You need to find a combination of various drivers in both OSes that work
> nice together and with the hardware. It's a trial and error process so
> unless someone has already solved this for you, expect to try lots of
> combinations.

On a Dell XPS laptop on occasions I used to find that there was no sound.  If 
I booted into MSWindows the OS would reset the sound, without having to login 
to a desktop and all would be fine thereafter.  Quite a random event, but 
thankfully I haven't had this problem for a few months now.  Perhaps the alsa 
drivers got better with time.  Now if this Radeon kernel regression problem 
were to go away too so that I can hibernate, I would be quite happy.  :-p
-- 
Regards,
Mick