On Tue, 11 May 2021 at 04:32, Ansuel Smith <ansuelsmth@xxxxxxxxx> wrote: > > On Tue, May 11, 2021 at 03:24:29AM +0100, Matthew Wilcox wrote: > > On Tue, May 11, 2021 at 04:16:54AM +0200, Ansuel Smith wrote: > > > Ipq8064 SoC requires larger IO_SPACE_LIMIT on second and third pci port. > > > > Do you really? I mean, yes, theoretically, I understand it, the > > hardware supports 64kB of I/O port space per root port. But I/O > > port space is rather deprecated these days. My laptop has precisely > > two devices with I/O ports, one with 64 bytes and the other with 32 > > bytes. Would you really suffer by allocating 16kB of I/O port > > space to each root port? > > We were talking about this in the other wrong patch. I also think this > much space looks wrong. The current ipq806x dts have this space so it's > actually broken from a long time. The only reason pci worked before was > because the pci driver didn't actually check if the settings were right. > New kernel introduced more checks and this problem showed up. (to be > more precise, the pci port are commonly used by the ath10k wifi and the > second ath10k wifi fails to init because of this problem) > If you can give me any hint on how to check if the space can be reduced > I would be very happy to investigate it. > In the driver I notice that the max buffer is set to 2k, could be this a > hint? > Could you share the output of lspci -vv from such a system? I agree with Matthew that fiddling with the size of the I/O space range probably papers over another problem, and with the odd exception, no PCIe card used on ARM systems actually uses their I/O BARs, even when they have them. (I used to carry a PCIe serial port card to UEFI plugfests because that was the only thing that would stop working if a system configured its I/O resource window incorrectly)
