Date: Thu, 7 Aug 2008 11:07:20 +0200
From: Marc Zyngier <maz@misterjones.org>
To: "Eric Miao" <eric.y.miao@gmail.com>
Cc: linux-kernel@vger.kernel.org,
       "Amit Walambe" <amit.walambe@eurotech-ltd.co.uk>
Subject: Re: [PATCH 1/5] Basic support for the Arcom/Eurotech Viper SBC.
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On Thu, 7 Aug 2008 11:50:57 +0800
"Eric Miao" <eric.y.miao@gmail.com> wrote:

Eric,

First, thanks for this in-depth review. I strongly agree with most of
your remarks. I just happend to have some questions regarding the
serial stuff:

> > +static struct plat_serial8250_port serial_platform_data[] = {
> > +       /* Internal UARTs */
> > +       {
> > +               .membase        = (void *)&FFUART,
> > +               .mapbase        = __PREG(FFUART),
> > +               .irq            = IRQ_FFUART,
> > +               .uartclk        = 921600 * 16,
> > +               .regshift       = 2,
> > +               .flags          = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
> > +               .iotype         = UPIO_MEM,
> > +       },
> > +       {
> > +               .membase        = (void *)&BTUART,
> > +               .mapbase        = __PREG(BTUART),
> > +               .irq            = IRQ_BTUART,
> > +               .uartclk        = 921600 * 16,
> > +               .regshift       = 2,
> > +               .flags          = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
> > +               .iotype         = UPIO_MEM,
> > +       },
> > +       {
> > +               .membase        = (void *)&STUART,
> > +               .mapbase        = __PREG(STUART),
> > +               .irq            = IRQ_STUART,
> > +               .uartclk        = 921600 * 16,
> > +               .regshift       = 2,
> > +               .flags          = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
> > +               .iotype         = UPIO_MEM,
> > +       },
> > +       /* External UARTs */
> > +       {
> > +               .mapbase        = VIPER_UARTA_PHYS,
> > +               .irq            = VIPER_UARTA_IRQ,
> > +               .uartclk        = 1843200,
> > +               .regshift       = 1,
> > +               .iotype         = UPIO_MEM,
> > +               .flags          = UPF_BOOT_AUTOCONF | UPF_IOREMAP |
> > +                                 UPF_SKIP_TEST,
> > +       },
> > +       {
> > +               .mapbase        = VIPER_UARTB_PHYS,
> > +               .irq            = VIPER_UARTB_IRQ,
> > +               .uartclk        = 1843200,
> > +               .regshift       = 1,
> > +               .iotype         = UPIO_MEM,
> > +               .flags          = UPF_BOOT_AUTOCONF | UPF_IOREMAP |
> > +                                 UPF_SKIP_TEST,
> > +       },
> > +       { },
> > +};
> > +
> > +static struct platform_device serial_device = {
> > +       .name                   = "serial8250",
> > +       .id                     = 0,
> > +       .dev                    = {
> > +               .platform_data  = serial_platform_data,
> > +       },
> > +       .num_resources          =
> > ARRAY_SIZE(viper_serial_resources),
> > +       .resource               = viper_serial_resources,
> > +};
> 
> We now have dedicated pxa serial driver, please use that
> driver for internal UARTs.

- Having both the pxa (for internal UARTs) and 8250 (for external
UARTs) serial drivers have a memory footprint impact. Ok, that's not
much.
- People using their old user-space with a new kernel will see their
serial port names shuffled (going from an all-ttyS? world to a mix of
ttySA? and ttyS?). Is there a way to avoid the confusion?

Thanks again,

	M.
-- 
A rat a day keeps the plague away.
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