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Date:      Thu, 29 May 2014 13:44:54 -0700
From:      John-Mark Gurney <jmg@funkthat.com>
To:        Olivier Houchard <cognet@freebsd.org>
Cc:        svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org
Subject:   Re: svn commit: r266855 - head/sys/dev/uart
Message-ID:  <20140529204454.GB43976@funkthat.com>
In-Reply-To: <201405291957.s4TJvp07085910@svn.freebsd.org>
References:  <201405291957.s4TJvp07085910@svn.freebsd.org>

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Olivier Houchard wrote this message on Thu, May 29, 2014 at 19:57 +0000:
> Author: cognet
> Date: Thu May 29 19:57:51 2014
> New Revision: 266855
> URL: http://svnweb.freebsd.org/changeset/base/266855
> 
> Log:
>   In the grab function, keep the bit 6 on in the IER, on XScale, using 0
>   turns the UART off, which is unfortunate if one want to use it as a console.
> 
> Modified:
>   head/sys/dev/uart/uart_dev_ns8250.c
> 
> Modified: head/sys/dev/uart/uart_dev_ns8250.c
> ==============================================================================
> --- head/sys/dev/uart/uart_dev_ns8250.c	Thu May 29 19:48:18 2014	(r266854)
> +++ head/sys/dev/uart/uart_dev_ns8250.c	Thu May 29 19:57:51 2014	(r266855)
> @@ -929,6 +929,7 @@ void
>  ns8250_bus_grab(struct uart_softc *sc)
>  {
>  	struct uart_bas *bas = &sc->sc_bas;
> +	struct ns8250_softc *ns8250 = (struct ns8250_softc*)sc;
>  
>  	/*
>  	 * turn off all interrupts to enter polling mode. Leave the
> @@ -936,7 +937,11 @@ ns8250_bus_grab(struct uart_softc *sc)
>  	 * All pending interupt signals are reset when IER is set to 0.
>  	 */
>  	uart_lock(sc->sc_hwmtx);
> -	uart_setreg(bas, REG_IER, 0);
> +	/*
> +	 * On XScale, bit 6 (0x40) is the UART Unit Enable, removing it
> +	 * turns the UART completely off,  so make sure it is stays there.
> +	 */
> +	uart_setreg(bas, REG_IER, ns8250->ier & 0x40);
>  	uart_barrier(bas);
>  	uart_unlock(sc->sc_hwmtx);
>  }

Should this be using ns8250->ier_mask instead of 0x40?

It also looks like AVILA doesn't have the hints to set this like
GUMSTIX does, and maybe adding this will help?

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."



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