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

[Chin Liang See <clsee@altera.com>]

On Thu, 2015-11-12 at 01:53 +0100, Marek Vasut wrote:
> On Thursday, November 12, 2015 at 01:49:09 AM, Chin Liang See wrote:
> > Hi Marek,
> > 
> > On Mon, 2015-11-09 at 17:02 +0100, Marek Vasut wrote:
> > > On Monday, November 09, 2015 at 04:46:54 PM, Stefan Roese wrote:
> > > > Hi Marek,
> > > 
> > > Hi!
> > > 
> > > > On 09.11.2015 14:49, Marek Vasut wrote:
> > > > 
> > > > <snip>
> > > > 
> > > > >>>> --- a/include/configs/socfpga_common.h
> > > > >>>> +++ b/include/configs/socfpga_common.h
> > > > >>>> @@ -73,7 +73,6 @@
> > > > >>>> 
> > > > >>>>    /*
> > > > >>>>    
> > > > >>>>     * Cache
> > > > >>>>     */
> > > > >>>> 
> > > > >>>> -#define CONFIG_SYS_ARM_CACHE_WRITEALLOC
> > > > >>>> 
> > > > >>>>    #define CONFIG_SYS_CACHELINE_SIZE 32
> > > > >>>>    #define CONFIG_SYS_L2_PL310
> > > > >>>>    #define CONFIG_SYS_PL310_BASE		SOCFPGA_MPUL2_ADDRESS
> > > > >>> 
> > > > >>> I hate to say it, but I am running into issues with this patch :-(
> > > > >> 
> > > > >> I'm sorry to hear this.
> > > > >> 
> > > > >>> I use a standard USB stick here and with this patch, I am getting
> > > > >>> the following failure (with enabled and disabled cache):
> > > > >>> 
> > > > >>> => usb reset
> > > > >>> resetting USB...
> > > > >>> USB0:   Core Release: 2.93a
> > > > >>> scanning bus 0 for devices... unable to get descriptor, error 0
> > > > >>> usb_new_device: Cannot read configuration, skipping device
> > > > >>> 058f:6387 1 USB Device(s) found
> > > > >>> 
> > > > >>>          scanning usb for storage devices... 0 Storage Device(s)
> > > > >>>          found
> > > > >>> 
> > > > >>> => dcache off
> > > > >>> => usb reset
> > > > >>> resetting 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
> > > > >>> 
> > > > >>> If I revert this patch, my USB stick works as well.
> > > > >>> 
> > > > >>> I am also aware that Stefan mentions that without this patch, cache
> > > > >>> is not enabled at all. On the other hand, I cannot find any
> > > > >>> obviously faulty behavior in the dwc2 driver, it does
> > > > >>> flush_dcache_range()/invalidate_dcache_range() in the right places.
> > > > >>> 
> > > > >>> Any ideas please ?
> > > > >> 
> > > > >> Perhaps its a timing related issue? As the code is executed faster
> > > > >> with cache enabled. Just an idea - perhaps there is still some ugly
> > > > >> code that doesn't do proper timer based loops / delays.
> > > > > 
> > > > > I doubt that's not the case. If I disable cache just around the hcdma
> > > > > bit in the driver (disable before the flush_dcache_range() and
> > > > > enable after invalidate_dcache_range() in the driver), it still
> > > > > fails.
> > > > 
> > > > Did you check if this problem is perhaps also related to Dinh's L2
> > > > cache patch:
> > > > 
> > > > 8d8e13e1 arm: socfpga: enable data/inst prefetch and shared override in
> > > > the L2
> > > > 
> > > > ?
> > > 
> > > Yes I did, but reverting this patch had no impact.
> > > 
> > > > 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


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


Thanks
Chin Liang