Hi Thomas, Bjorn, On 6/23/20 1:49 AM, Bjorn Helgaas wrote: > On Mon, Jun 22, 2020 at 08:40:33PM +0200, Thomas Petazzoni wrote: >> On Mon, 22 Jun 2020 12:25:16 -0500 >> Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: >> >>>> As a result of the requirement above, without this patch, MSI won't >>>> function and therefore some devices won't operate properly without >>>> pci=nomsi. >>> Does that mean MSIs never worked at all with mvebu? >> They definitely worked. I think what happens is that this register was >> normally setup by the vendor-specific bootloader, and thanks to >> firmware initialization, Linux had MSIs working properly. >> >> With other bootloaders that initialize the PCIe block differently, or >> even not at all, it became clear this init was missing in Linux. > That would be very useful information to include in the commit log. Thanks. I will add it to the commit message. > > Are there any other similar bugs lurking? Other registers where we > implicitly rely on the bootloader to do something? I don't think that any PCI driver writer can answer this question for sure. I can however confirm that this driver, on the a385, works with no u-boot PCIe initialization. As for other subsystems PCI is dependent on (e.g. SerDes, etc), I can't say for sure. -- - Shmuel Hazan mailto:sh@xxxxxxxxxx | tel:+972-523-746-435 | http://tkos.co.il
