From: alexandre.belloni@free-electrons.com (Alexandre Belloni)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: at91: debug: use DEBUG_UART_VIRT
Date: Tue, 7 Jun 2016 18:23:01 +0200 [thread overview]
Message-ID: <20160607162301.GL3363@piout.net> (raw)
In-Reply-To: <5756ECC5.6020908@atmel.com>
On 07/06/2016 at 17:48:21 +0200, Nicolas Ferre wrote :
> Le 07/06/2016 17:24, Alexandre Belloni a ?crit :
> > AT91 still uses an offset (0x0100 0000) from the physical address to map
> > the debug UART. This is unfortunate as for some platforms (sama5d3 and
> > earlier), it ends up in the PCI zone and PCI is enabled in multi_v7.
> > Switch to DEBUG_UART_VIRT to solve that.
> >
> > Tested on sama5d3 and 9g20.
> >
> > Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
>
> People using their old defconfigs must pay attention to this change...
> but it's true that it's a debug configuration anyway...
>
I really doubt people are letting DEBUG_LL enabled in a production
kernel...
> > diff --git a/arch/arm/include/debug/at91.S b/arch/arm/include/debug/at91.S
> > index d4ae3b8e2426..0098401e5aeb 100644
> > --- a/arch/arm/include/debug/at91.S
> > +++ b/arch/arm/include/debug/at91.S
> > @@ -9,14 +9,6 @@
> > *
> > */
> >
> > -#ifdef CONFIG_MMU
> > -#define AT91_IO_P2V(x) ((x) - 0x01000000)
> > -#else
> > -#define AT91_IO_P2V(x) (x)
> > -#endif
> > -
> > -#define AT91_DEBUG_UART_VIRT AT91_IO_P2V(CONFIG_DEBUG_UART_PHYS)
> > -
> > #define AT91_DBGU_SR (0x14) /* Status Register */
> > #define AT91_DBGU_THR (0x1c) /* Transmitter Holding Register */
> > #define AT91_DBGU_TXRDY (1 << 1) /* Transmitter Ready */
> > @@ -24,7 +16,7 @@
> >
> > .macro addruart, rp, rv, tmp
> > ldr \rp, =CONFIG_DEBUG_UART_PHYS @ System peripherals (phys address)
> > - ldr \rv, =AT91_DEBUG_UART_VIRT @ System peripherals (virt address)
> > + ldr \rv, =CONFIG_DEBUG_UART_VIRT @ System peripherals (virt address)
>
> Shouldn't we protect the use of this defined value with some
> #warning "Beware the value CONFIG_DEBUG_UART_VIRT haven't been defined:
> is it intentional"
> or even #error?
>
> or something like that?
>
Well, those that are using this feature are supposed to know what they
are doing. There is now protection for CONFIG_DEBUG_UART_PHYS anyway.
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
next prev parent reply other threads:[~2016-06-07 16:23 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-07 15:24 [PATCH] ARM: at91: debug: use DEBUG_UART_VIRT Alexandre Belloni
2016-06-07 15:48 ` Nicolas Ferre
2016-06-07 16:23 ` Alexandre Belloni [this message]
2016-06-08 7:17 ` Nicolas Ferre
2016-06-08 8:18 ` Nicolas Ferre
2016-06-10 15:10 ` Alexandre Belloni
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160607162301.GL3363@piout.net \
--to=alexandre.belloni@free-electrons.com \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).