From: Feng Tang <feng.tang@intel.com>
To: Alan Cox <alan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>,
"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
"greg@kroah.com" <greg@kroah.com>,
the arch/x86 maintainers <x86@kernel.org>
Subject: Re: [PATCH 2/5] hsu, earlyprintk: add early printk for hsu_port2 console
Date: Tue, 7 Sep 2010 09:28:53 +0800 [thread overview]
Message-ID: <20100907092853.1aa1aa24@feng-i7> (raw)
In-Reply-To: <20100906151542.2b155adf@linux.intel.com>
On Mon, 6 Sep 2010 22:15:42 +0800
Alan Cox <alan@linux.intel.com> wrote:
>
> > > + /* GPIO workaround */
> > > + set_fixmap_nocache(FIX_EARLYCON_MEM_BASE,
> > > MFD_GPIO_HSU_REG);
> > > + phsu = (void *)(__fix_to_virt(FIX_EARLYCON_MEM_BASE) +
> > > + (MFD_GPIO_HSU_REG & (PAGE_SIZE - 1)));
> > > +
> > > + *((u32 *)phsu) = 0x55465;
> >
> > What does 0x55465 stand for?
>
> It's a firmware fixup. Its a magic value (even to most of us who work
> here ;)). Feng - am I right in thinking we don't need that anyway with
> the current firmware ?
Yes, it's a fixup for firmware, it set GPIO controller's register to correctly
configure the GPIO lines used by HSU. Latest firmware already fix that, and
it could be removed.
Thank you both for the comments, will try to address them and make a v2.
Thanks,
Feng
next prev parent reply other threads:[~2010-09-07 1:09 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-06 12:39 [PATCH 1/5] mrst_earlyprintk: add a kmsg_dumper to dump the printk buffer when panic Alan Cox
2010-09-06 12:39 ` [PATCH 2/5] hsu, earlyprintk: add early printk for hsu_port2 console Alan Cox
2010-09-06 14:17 ` Ingo Molnar
2010-09-06 14:15 ` Alan Cox
2010-09-06 16:18 ` Ingo Molnar
2010-09-07 1:28 ` Feng Tang [this message]
2010-09-06 12:39 ` [PATCH 3/5] hsu, earlyprintk: remove the GPIO work around Alan Cox
2010-09-06 12:40 ` [PATCH 4/5] serial: mrst_max3110: some code cleanup Alan Cox
2010-09-06 12:40 ` [PATCH 5/5] mrst_max3110: Make the IRQ option runtime Alan Cox
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