[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <3df135a2-17f5-d6c6-b4a8-e1a60e254297@roeck-us.net>
Date: Sun, 24 Apr 2022 08:28:19 -0700
From: Guenter Roeck <linux@...ck-us.net>
To: Arnd Bergmann <arnd@...nel.org>
Cc: Robert Jarzmik <robert.jarzmik@...e.fr>,
Linux ARM <linux-arm-kernel@...ts.infradead.org>,
Arnd Bergmann <arnd@...db.de>, Daniel Mack <daniel@...que.org>,
Haojian Zhuang <haojian.zhuang@...il.com>,
Marek Vasut <marek.vasut@...il.com>,
Philipp Zabel <philipp.zabel@...il.com>,
Lubomir Rintel <lkundrak@...sk>,
Paul Parsons <lost.distance@...oo.com>,
Tomas Cech <sleep_walker@...e.com>,
Sergey Lapin <slapin@...fans.org>,
Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
Michael Turquette <mturquette@...libre.com>,
Stephen Boyd <sboyd@...nel.org>,
"Rafael J. Wysocki" <rafael@...nel.org>,
Viresh Kumar <viresh.kumar@...aro.org>,
Dmitry Torokhov <dmitry.torokhov@...il.com>,
Ulf Hansson <ulf.hansson@...aro.org>,
Dominik Brodowski <linux@...inikbrodowski.net>,
Helge Deller <deller@....de>, Mark Brown <broonie@...nel.org>,
Linus Walleij <linus.walleij@...aro.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
"open list:BROADCOM NVRAM DRIVER" <linux-mips@...r.kernel.org>,
IDE-ML <linux-ide@...r.kernel.org>,
linux-clk <linux-clk@...r.kernel.org>,
Linux PM list <linux-pm@...r.kernel.org>,
"open list:HID CORE LAYER" <linux-input@...r.kernel.org>,
patches@...nsource.cirrus.com, linux-leds@...r.kernel.org,
linux-mmc <linux-mmc@...r.kernel.org>,
linux-mtd <linux-mtd@...ts.infradead.org>,
linux-rtc@...r.kernel.org, USB list <linux-usb@...r.kernel.org>,
Linux Fbdev development list <linux-fbdev@...r.kernel.org>,
dri-devel <dri-devel@...ts.freedesktop.org>,
ALSA Development Mailing List <alsa-devel@...a-project.org>
Subject: Re: [PATCH v2 00/48] ARM: PXA multiplatform support
On 4/24/22 01:52, Arnd Bergmann wrote:
> On Sun, Apr 24, 2022 at 4:09 AM Guenter Roeck <linux@...ck-us.net> wrote:
>> On 4/23/22 12:55, Arnd Bergmann wrote:
>>> On Sat, Apr 23, 2022 at 1:41 AM Guenter Roeck <linux@...ck-us.net> wrote:
>>>> On Sat, Apr 23, 2022 at 12:04:31AM +0200, Arnd Bergmann wrote:
>>>
>>> Odd, I can't reproduce this at all. Do you get any console output at
>>> all for this?
>>>
>>> Is this the plain omap1_defconfig, or something else?
>>>
>>
>> No, it is my own sx1 specific configuration.
>>
>> https://github.com/groeck/linux-build-test/blob/master/rootfs/arm/qemu_sx1_defconfig
>>
>> I don't recall where I got it from but ...
>
> Ok, that explains it, thanks!
>
> I fixed all the defconfig files that come with the kernel, but for your own
> ones you have to add
>
> # CONFIG_ARCH_MULTI_V7 is not set
>
> into the defconfig file, otherwise the multiplatform target defaults to
> an ARMv7 instead of ARMv5 build. For an OMAP15xx as in the SX1,
> you also need to enable CONFIG_ARCH_MULTI_V4T.
>
> This is slightly unfortunate, but I don't see any way to avoid it, and the
> modified defconfig will still work fine with older kernel trees.
>
Yes, that works. I changed it in my configuration.
>>> One thing I keep having to apply myself is this snippet:
>>>
>>> diff --git a/arch/arm/mm/proc-arm925.S b/arch/arm/mm/proc-arm925.S
>>> index 0bfad62ea858..87c695703580 100644
>>> --- a/arch/arm/mm/proc-arm925.S
>>> +++ b/arch/arm/mm/proc-arm925.S
>>> @@ -441,7 +441,6 @@ __arm925_setup:
>>>
>>> #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
>>> mov r0, #4 @ disable write-back
>>> on caches explicitly
>>> - mcr p15, 7, r0, c15, c0, 0
>>> #endif
>>
>> it does not have CONFIG_CPU_DCACHE_WRITETHROUGH enabled.
>
> Maybe it was disabled explicitly for the sx1_defconfig because of this
> bug. I would think that this is required for actual sx1 hardware because the
> option is default-enabled for ARM925T, and that CPU core is exclusively
> used in OMAP15xx.
>
That looks like a bug in qemu. ARM925T instruction support is limited to V4T
instructions. qemu doesn't have explicit 5T support. It is either V4T
or V5.
Guenter
Powered by blists - more mailing lists