From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Wed, 11 Jul 2018 16:05:43 +0200 Subject: [U-Boot] SoCFPGA PL330 DMA driver and ECC scrubbing In-Reply-To: References: <73d4ce24-2b78-d27c-1dbf-ebef00e9689b@gmail.com> <4c001307-e555-b085-9982-4a6e0f8fb669@gmail.com> <57651474-ac6c-b5d2-e675-1d01de30dbca@denx.de> <277351bc-f902-826b-f9f3-f00f380b1e81@denx.de> <1aecf0e6-56f1-9254-25d8-5d45c5c9be59@gmail.com> <5dceaad3-353e-b015-0871-93986f3ebc5d@denx.de> <9db37c5e-abf9-cbbf-0e6b-b269dfcd6528@gmail.com> <04312468-3dcc-3fa4-3e70-2fcc07e1051e@denx.de> <8523e998-9ae2-e713-60ec-6d740ab0d3c4@gmail.com> <7d7d8558-98f2-c0df-02ad-a38727e61d71@gmail.com> <5a6e8f4a-01b7-634f-2cca-79a4f11f91ff@gmail.com> <9ba3d878-7783-30a8-d1ac-1085b89da393@denx.de> Message-ID: <69582fee-a7ca-bfad-3e44-19eeb218643f@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: u-boot@lists.denx.de On 07/11/2018 03:56 PM, Jason Rush wrote: > On 7/11/2018 8:48 AM, Marek Vasut wrote: >> On 07/11/2018 03:49 PM, Jason Rush wrote: >>> On 7/11/2018 3:55 AM, Marek Vasut wrote: >>>> On 07/11/2018 05:11 AM, Jason Rush wrote: >>>> [...] >>>> >>>>>>>>> However, if I press the HPS_RST push button on the SoCKit (which is connected >>>>>>>>> to power on reset), occasionally U-Boot will lock up while booting.  It always >>>>>>>>> boots and operates correctly from the initial power on, but it almost always >>>>>>>>> fails to boot after pressing the HPS_RST button. >>>>>>>>> >>>>>>>>> Usually after pressing the HPS_RST button, U-Boot makes it past the SPL, and >>>>>>>>> hangs somewhere after the call to setup_reloc() in ./common/board_f.c.  Once >>>>>>>>> it hangs there, pressing the HPS_RST button again usually causes the SPL to >>>>>>>>> hang while setting up the MMU (before my call to memset).  Eventually the >>>>>>>>> WDT kicks in, and it just keeps hanging up in the same place.  Once it gets in >>>>>>>>> this mode, the only way to recover it is by toggling power on the board. >>>>>>>>> >>>>>>>>> I spent a bunch of time today trying to track down where it was hanging, but >>>>>>>>> I couldn't pin point anything.  The MMU tables looked correct.  The MMU >>>>>>>>> registers looked good.  I'm not sure the best way to debug what's going on. >>>>>>>> Try triggering warm reset and cold reset via the reset register: >>>>>>>> >>>>>>>> mw 0xffd05004 1 >>>>>>>> mw 0xffd05004 2 >>>>>>>> >>>>>>>> Does it hang in one case and not in the other ? >>>>>>>> >>>>>>> It hangs in both cases. >>>>>>> >>>>>>> I did find that if I do not metset the last 1MiB of DRAM with the cache on, >>>>>>> both warm and cold resets work. >>>>>>> >>>>>>> I changed the ecc scrubbing to zero out the first 0x8000 bytes and the last >>>>>>> 0x10000 bytes before the MMU is setup and I enable dcache.  Then with >>>>>>> the dcache enabled, I zero out the rest of memory.  The resets work in this >>>>>>> case as well.  So there seems to be some side effect of clearing out the >>>>>>> relocate address space with the cache on. >>>>>> Can you investigate ? >>>>>> >>>>> I'd be happy to investigate more, but I'm not really sure what >>>>> my next step should be. >>>>> >>>>> Something appears to be happening differently when U-Boot >>>>> relocates if the dcache is on.  But don't know how to track it >>>>> down. >>>> IIRC I disabled cache after scrubbing. >>> My mistake.  I did disable the dcache after scrubbing too.  The >>> code is almost identical to the Arria10 code where after >>> scrubbing it flushes the dcache, then turns it off. >>> >>> The weird reset problems happens if I scrub the area where >>> u-boot relocates to with the dcache on, then turn dcache off. >>> >>> I tried to also tried turning the MMU off, but that didn't help. >> Maybe there are some data used by the SPL there ? I think the SPL has >> malloc area in RAM at some point. >> > I thought something similar, so I narrowed it down to clearing > just from where U-Boot relocates to the end of DRAM.  If I'm > correct, that includes where U-Boot relocates and where the > MMU tables are normally stored. Hm, although, I think if you do the scrubbing right after the DRAM controller gets inited, there isn't anything in the DRAM yet. You might need to keep digging, since this is odd. -- Best regards, Marek Vasut