[U-Boot] [PATCH] arm: socfpga: Fix cache configuration

[Marek Vasut <marex@denx.de>]

On Thursday, November 12, 2015 at 03:33:42 AM, Chin Liang See wrote:

[...]

> > > > > I just noticed, that here the L2 cache gets disabled and is not
> > > > > enabled again in function v7_outer_cache_enable(). This looks a
> > > > > bit suspicious.
> > > > > 
> > > > > Dinh, did you perhaps miss to re-enable the L2 cache after the
> > > > > aux_ctrl register setup again?
> > > > 
> > > > I guess we should pester Dinh now :-)
> > > 
> > > I recompiled the latest source and it works for me.
> > > Here is the printout message.
> > > Wonder any modification against commit a55f28624e97e1e43ac?
> > > 
> > > 
> > > U-Boot 2015.10-08073-ga55f286 (Nov 11 2015 - 23:19:06 +0800)
> > > 
> > > CPU:   Altera SoCFPGA Platform
> > > FPGA:  Altera Cyclone V, SE/A6 or SX/C6 or ST/D6, version 0x0
> > > BOOT:  SD/MMC External Transceiver (1.8V)
> > > 
> > >        Watchdog enabled
> > > 
> > > I2C:   ready
> > > DRAM:  1 GiB
> > > MMC:   SOCFPGA DWMMC: 0
> > > *** Warning - bad CRC, using default environment
> > > 
> > > In:    serial
> > > Out:   serial
> > > Err:   serial
> > > Model: Altera SOCFPGA Cyclone V SoC Development Kit
> > > Net:
> > > Error: ethernet at ff702000 address not set.
> > > No ethernet found.
> > > Hit any key to stop autoboot:  0
> > > => dcache
> > > Data (writethrough) Cache is ON
> > > => icache
> > > Instruction Cache is ON
> > > => usb start
> > > starting USB...
> > > USB0:   Core Release: 2.93a
> > > scanning bus 0 for devices... 2 USB Device(s) found
> > > 
> > >        scanning usb for storage devices... 1 Storage Device(s) found
> > > 
> > > => usb info
> > > 1: Hub,  USB Revision 1.10
> > > 
> > >  -  U-Boot Root Hub
> > >  - Class: Hub
> > >  - PacketSize: 8  Configurations: 1
> > >  - Vendor: 0x0000  Product 0x0000 Version 0.0
> > >  
> > >    Configuration: 1
> > >    - Interfaces: 1 Self Powered 0mA
> > >    
> > >      Interface: 0
> > >      - Alternate Setting 0, Endpoints: 1
> > >      - Class Hub
> > >      - Endpoint 1 In Interrupt MaxPacket 2 Interval 255ms
> > > 
> > > 2: Mass Storage,  USB Revision 2.0
> > > 
> > >  - SanDisk  SDDR-113 000000009412
> > >  - Class: (from Interface) Mass Storage
> > >  - PacketSize: 64  Configurations: 1
> > >  - Vendor: 0x0781  Product 0xa7c1 Version 148.18
> > >  
> > >    Configuration: 1
> > >    - Interfaces: 1 Bus Powered 500mA
> > >    
> > >      Interface: 0
> > >      - Alternate Setting 0, Endpoints: 2
> > >      - Class Mass Storage, Transp. SCSI, Bulk only
> > >      - Endpoint 1 In Bulk MaxPacket 512
> > >      - Endpoint 2 Out Bulk MaxPacket 512
> > 
> > Yeah, that's because you're using high-quality USB sticks which leave
> > skid marks on the USB port. Now try with some dirt cheap USB 2.0 stick.
> > 
> > 058f:6387 Alcor Micro Corp. Flash Drive
> > 
> > The thing above is my absolute fav when it comes to testing corner cases:
> > http://www.intenso.de/produkte.php?kategorie=23&&produkt=1255723475

Hi!

> It takes some amount of time for digging out a USB 2.0 stick :)

Well sorry about living in a developing country ;-)

> But it still work for me as below.
> Let me check out the code and see any clue.
> 
> 
> 2: Mass Storage,  USB Revision 2.0
>  -          USB DISK 2.0     0781076602A6
>  - Class: (from Interface) Mass Storage
>  - PacketSize: 64  Configurations: 1
>  - Vendor: 0x13fe  Product 0x1e00 Version 1.16
>    Configuration: 1
>    - Interfaces: 1 Bus Powered 200mA
>      Interface: 0
>      - Alternate Setting 0, Endpoints: 2
>      - Class Mass Storage, Transp. SCSI, Bulk only
>      - Endpoint 1 In Bulk MaxPacket 512
>      - Endpoint 2 Out Bulk MaxPacket 512

Fascinating. Could it be that it's only these really crappy USB sticks which
trigger some odd condition in the controller ? I will dig out the trusty SoCDK
and check it there this week.

btw. these Alcor sticks work for me in Linux 3.18.x, but seems like that's not 
always the case:
http://comments.gmane.org/gmane.linux.usb.general/86117