From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Hurley <peter-WaGBZJeGNqdsbIuE7sb01tBPR1lH4CV8@public.gmane.org>
Subject: Re: [PATCH 3/7] tty: 8250: omap: introduce function to update mdr1
Date: Wed, 08 Jul 2015 20:29:19 -0400
Message-ID: <559DC05F.9070707@hurleysoftware.com>
References: <cover.1436174801.git.nsekhar@ti.com> <597e0f4bf4455cb7755851f5c34a02fbdd0d4aeb.1436174801.git.nsekhar@ti.com>
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To: Sekhar Nori <nsekhar-l0cyMroinI0@public.gmane.org>, Greg Kroah-Hartman <gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>, Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
Cc: Linux OMAP Mailing List <linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Pawel Moll <pawel.moll-5wv7dgnIgG8@public.gmane.org>, Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>, Ian Campbell <ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org>, Kumar Gala <galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>, Device Tree Mailing List <devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, John Ogness <john.ogness-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>, Sebastian Andrzej Siewior <bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>, linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
List-Id: devicetree@vger.kernel.org

Hi Sekhar,

On 07/06/2015 05:47 AM, Sekhar Nori wrote:
> updating mdr1 register on OMAP needs to take care of
> errata i202. Introduce a function to update mdr1.
> 
> This will be useful later on when mdr1 needs to be
> written to from other places. No functional change.

This changelog is not clear. May I suggest:

serial: 8250_omap: Refactor MDR1 update

The errata [1] workaround implemented in follow-on patch,
"serial: 8250_omap: workaround errata on disabling UART after using DMA",
requires MDR1 register programming.

Extract MDR1 register update into helper function, omap8250_update_mdr1().

[1] Advisory 21 in http://www.ti.com/lit/er/sprz408b/sprz408b.pdf


Regards,
Peter Hurley

> Signed-off-by: Sekhar Nori <nsekhar-l0cyMroinI0@public.gmane.org>
> ---
>  drivers/tty/serial/8250/8250_omap.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
> index 20c5b9c4c288..d9c96b993a84 100644
> --- a/drivers/tty/serial/8250/8250_omap.c
> +++ b/drivers/tty/serial/8250/8250_omap.c
> @@ -232,6 +232,15 @@ static void omap8250_update_scr(struct uart_8250_port *up,
>  	serial_out(up, UART_OMAP_SCR, priv->scr);
>  }
>  
> +static void omap8250_update_mdr1(struct uart_8250_port *up,
> +				 struct omap8250_priv *priv)
> +{
> +	if (priv->habit & UART_ERRATA_i202_MDR1_ACCESS)
> +		omap_8250_mdr1_errataset(up, priv);
> +	else
> +		serial_out(up, UART_OMAP_MDR1, priv->mdr1);
> +}
> +
>  static void omap8250_restore_regs(struct uart_8250_port *up)
>  {
>  	struct omap8250_priv *priv = up->port.private_data;
> @@ -282,11 +291,9 @@ static void omap8250_restore_regs(struct uart_8250_port *up)
>  	serial_out(up, UART_XOFF1, priv->xoff);
>  
>  	serial_out(up, UART_LCR, up->lcr);
> -	/* need mode A for FCR */
> -	if (priv->habit & UART_ERRATA_i202_MDR1_ACCESS)
> -		omap_8250_mdr1_errataset(up, priv);
> -	else
> -		serial_out(up, UART_OMAP_MDR1, priv->mdr1);
> +
> +	omap8250_update_mdr1(up, priv);
> +
>  	up->port.ops->set_mctrl(&up->port, up->port.mctrl);
>  }
>  
> 

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