Messages in this thread | | | From | <> | Subject | Re: Regression: memory corruption on Atmel SAMA5D31 | Date | Thu, 30 Jun 2022 09:23:28 +0000 |
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On 6/30/22 08:20, Peter Rosin wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > Hi!
Hi, Peter! > > 2022-06-27 at 18:53, Tudor.Ambarus@microchip.com wrote: >> On 6/27/22 15:26, Tudor.Ambarus@microchip.com wrote: >>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >>> >>> On 6/21/22 13:46, Peter Rosin wrote: >>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >>>> >>>> 2022-06-20 at 16:22, Tudor.Ambarus@microchip.com wrote: >>>>> >>>>>> >>>>>> git@github.com:ambarus/linux-0day.git, branch dma-regression-hdmac-v5.18-rc7-4th-attempt >>>>>> >>>>> >>>>> Hi, Peter, >>>>> >>>>> I've just forced pushed on this branch, I had a typo somewhere and with that fixed I could >>>>> no longer reproduce the bug. Tested for ~20 minutes. Would you please test last 3 patches >>>>> and tell me if you can still reproduce the bug? >>>> >>>> Hi! >>>> >>>> I rebased your patches onto my current branch which is v5.18.2 plus a few unrelated >>>> changes (at least they are unrelated after removing the previous workaround to disable >>>> nand-dma entirely). >>>> >>>> The unrelated patches are two backports so that drivers recognize new compatibles [1][2], >>>> which should be completely harmless, plus a couple of proposed fixes that happens to fix >>>> eeprom issues with the at91 I2C driver from Codrin Ciubotariu [3]. >>>> >>>> On that kernel, I can still reproduce. It seems a bit harder to reproduce the problem now >>>> though. If the system is otherwise idle, the sha256sum test did not reproduce in a run of >>>> 150+ attempts, but if I let the "real" application run while I do the test, I get a failure rate >>>> of about 10%, see below. The real application burns some CPU (but not all of it) and >>>> communicates with HW using I2C, native UARTs and two of the four USB-serial ports >>>> (FTDI, with the latency set to 1ms as mentioned earlier), so I guess there is more DMA >>>> pressure or something? There is a 100mbps network connection, but it was left "idle" >>>> during this test. >>>> >>> >>> Thanks, Peter. >>> I got back to the office, I'm rechecking what could go wrong. >>> >> >> Hi, Peter, >> >> Would you please help me with another round of testing? I have difficulties >> in reproducing the bug and maybe you can speed up the process while I copy >> your testing setup. I made two more patches on top of the same branch [1]. >> My assumption is that the last problem that you saw is that a transfer >> could be started multiple times. I think these are the last less invasive >> changes that I try, I'll have to rewrite the logic anyway. >> >> Thanks! >> >> [1] To github.com:ambarus/linux-0day.git >> cbb2ddca4618..79c7784dbcf2 dma-regression-hdmac-v5.18-rc7-4th-attempt -> dma-regression-hdmac-v5.18-rc7-4th-attempt > > I was out of office, but I managed to get a test running over night and can > report that It still fails. This is a longer run of about 500 with a failure > rate of 5% compared to the last time when the failure rate was 10%. I tend
Thanks!
> to think that the observed difference in failure rate may well be statistical > noise, but who knows? Would it be useful with a longer run without the last > two patches to see if they make a difference?
I pushed another patch were I added a write mem barrier to make sure everything is in place before starting the transfer. Could you also take the last patch and re-test if it's not too complicated? I still can't reproduce it on my side, I'm checking what else I can add to stress test the DMA.
Thanks! ta
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