Hi, Le lundi 15 janvier 2018 à 17:47 +0800, Chen-Yu Tsai a écrit : > On Mon, Jan 15, 2018 at 5:41 PM, Paul Kocialkowski <[email protected]> > wrote: > > Hi, > > > > I'm using a Lamobo-R1 with the latest stable U-Boot (2017.11) and > > Linux > > (4.14) as a server that runs continuously. It has a SATA disk > > attached > > to the SATA connector and it is powered by the microUSB PSU that was > > sold with the board. > > > > It seems that whenever I try to access the SATA disk with lots of > > I/O > > (say, copying over a very large file, encoding a video, etc), I get > > a > > "Unable to handle kernel paging request" error. > > > > I suppose it could be that the AHCI code is messing with the page > > table > > when it's under heavy load (probably not very likely), or that > > access to > > the SATA disk requires more power than there is available and causes > > a > > current surge that leads DRAM to be under-powered and corrupt the > > page > > table. > > > > Note that I have tried lowering the DRAM frequency from 432 MHz to > > 408 > > MHz (increased instability) and 384 MHz (comparable with 432 MHz), > > so I > > definitely believe this is DRAM-related one way or another. > > > > I have also read https://linux-sunxi.org/Lamobo_R1#Powering_the_boar > > d > > which indicates that the microUSB power supply is limited to 1.8A > > and that the design is "often somewhat unreliable". > > > > Has anyone experiences similar issues or have some comments to share > > on > > this kind of issue? > > Have you tried powering the board directly from the GPIO pins, as > described on the wiki page you linked to?
The wiki page mentions powering the board directly from the VBAT connector. However, I would like to use the same USB power supply (that provides up to 3A at 5V) and would like to avoid hacking together some connector adapter. I looked-up the AXP2009 datasheet and it appears that the AC port (connected to the USB connector) can only source 1.5 A and the PMU will switch to VBAT if more is needed. So I figured that I could connect VBAT and the VBUS from the supply together, but I'm not sure it's safe having no idea of the internal structure of the AXP209. Anyway, I also found out that the SATA supply can be routed either to IPSOUT (default) or to VBAT directly through a 0-Ohm resistor configuration (R6/R51). What I will probably end up doing is to bring VBUS to one end of the 0-Ohm resistor to route VBUS instead of IPSOUT. Note that this is not direclty the SATA supply but the input of its regulator, so dedicated circuitry for regulation and filtering is there aswell. I will probably report back if I run into issues with this setup, but it should hopefully provide the SATA disk with enough current at all times. Cheers, -- Paul Kocialkowski, developer of free digital technology and hardware support Website: https://www.paulk.fr/ Coding blog: https://code.paulk.fr/ Git repositories: https://git.paulk.fr/ https://git.code.paulk.fr/ -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
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