On Wed, Feb 27, 2019 at 8:52 AM Leigh Brown leigh@solinno.co.uk wrote:

Hi Adam,

Thanks very much for your response.

On 2019-02-27 12:50, Adam Ford wrote:

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On Wed, Feb 27, 2019 at 5:32 AM Leigh Brown leigh@solinno.co.uk wrote:

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Hello,

Vagrant Cascadian asked for people to test the version of u-boot packaged for Debian Buster. I tested u-boot on my Dreamplug and found it was not working correctly. I raised a bug for Debian[1] but I have also tested with the mainline version of u-boot and found the same issues.

The first issue is that the following commit caused u-boot to no longer be able to access usb storage on the Dreamplug:

commit 93b283d49f933f95f3a6f40762936f454ac655a8 Author: Adam Ford aford173@gmail.com Date: Thu Aug 16 13:23:11 2018 -0500

Sorry about that.

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 ARM: CPU: arm926ejs: Consolidate cache routines to common file

 Four different boards had different options for enabling cache
 that were virtually all the same.  This consolidates these
 common functions into arch/arm/cpu/arm926ejs/cache.c

 This also has the positive side-effect of enabling cache on
 the Davinci (da850) boards.

 Signed-off-by: Adam Ford <aford173@gmail.com>
 [trini: Add mach-at91 to the list of consolidations]
 Signed-off-by: Tom Rini <trini@konsulko.com>

I don't have much knowledge of ARM caching, but the following patch makes it work again on my Dreamplug.

I am not that familiar with the ARM caching either, I was just hoping to enable it on the da850 board and compared the various code chunks between ARM 926 boards and noticed a common thread. Tom took it and added some more.

Okay. Hopefully Tom can comment on my proposed fixes.

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diff --git a/arch/arm/mach-kirkwood/cpu.c b/arch/arm/mach-kirkwood/cpu.c index d54de53f31..8a065d73ae 100644 --- a/arch/arm/mach-kirkwood/cpu.c +++ b/arch/arm/mach-kirkwood/cpu.c @@ -291,7 +291,6 @@ int arch_misc_init(void) temp |= (1 << 22); writefr_extra_feature_reg(temp);

#ifndef CONFIG_SYS_ICACHE_OFF

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•   icache_enable();
  

#endif

Instead of commenting out that line, try defining CONFIG_SYS_ICACHE_OFF in your header like you did for the CONFIG_SYS_DCACHE_OFF and encapsulate the function call with ifdef's so any other kirkwood processors can enable/disable it independently.

The reason I removed that line is because icache_enable() is called from enable_caches() which is called from initr_caches() which is in the list of functions in init_sequence_r[] prior to arch_misc_init(). In other words, it will already have been called by then if CONFIG_SYS_ICACHE_OFF is not set. Does that make sense?

That makes a lot of sense to me.

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    /* Change reset vector to address 0x0 */
    temp = get_cr();
    set_cr(temp & ~CR_V);

diff --git a/include/configs/dreamplug.h b/include/configs/dreamplug.h index f4d717213c..6348935c68 100644 --- a/include/configs/dreamplug.h +++ b/include/configs/dreamplug.h @@ -79,4 +79,6 @@ #define CONFIG_SYS_ATA_IDE0_OFFSET MV_SATA_PORT0_OFFSET #endif /*CONFIG_MVSATA_IDE*/

+#define CONFIG_SYS_DCACHE_OFF

#define CONFIG_SYS_ICACHE_OFF

The reason I have not done this is because the Kirkwood arch_misc_init() function was already unconditionally enabling the instruction cache, so we want to retain that behaviour - I think. I hope that makes sense.

That makes a lot of sense too.

adam

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• #endif /* _CONFIG_DREAMPLUG_H */

I'd be grateful if someone could take a look. If you need me to do any testing or provide any more information, please let me know.

I found another issue (documented in the same bug). I'll send a separate email about that.

Regards,

Leigh.

-- [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=923379

Regards,

Leigh.