* Olof Johansson wrote: > Hi, > > On Thu, Nov 24, 2011 at 11:57 AM, Thierry Reding > <thierry.reding@xxxxxxxxxxxxxxxxx> wrote: > > Hi, > > > > I was wondering whether anyone had gotten MSI to work with Tegra2? The code > > in arch/arm/mach-tegra/pcie.c has some comments saying that it currently > > isn't supported. > > > > Looking through the Tegra2 TRM didn't show much related to MSI. In particular > > there doesn't seem to be any mention of the AFI controller or any of it's > > registers (except of how to enable/disable the AFI clock or reset the > > controller). > > > > Furthermore I wasn't able to get PCIe to work on Harmony with a mainline > > kernel. Is something missing or am I just doing something wrong? > > I think there might be an issue with regulator setup for pci-e, I got > a vague bug report off-list from someone about it but I'm normally not > using devices with pci-e on them myself. I've verified with a hardware engineer that the voltages indeed seem correct. Even the PCIe reference clock can be measured at the mini-PCIe connectors. So something must be going right. > Note that trimslice does enable pci-e, so you can use that for comparison. Trimslice doesn't seem to do much regarding PCIe initialization. It basically just calls the tegra_pcie_init() and has the pinmuxing set up via the pinmux table as opposed to Harmony. I'm thinking about ordering a Trimslice to use for comparison. Has anyone else verified that mainline has working PCIe for Trimslice? I think Mike Rapoport is no longer a regular on this list. His last commits seem to indicate that PCIe was working on Harmony as well at the time, so I'm a little confused about what might have happened since then. > > I can make > > it work with the Vibrante kernel, but that doesn't have MSI support either. > > Since we're looking at designing an evaluation board with PCIe support I'm > > very interested in seeing this supported in mainline. If there's anything I > > can do to help, please let me know. Also if anyone can provide more insight > > than the TRM, that would be great. > > I have no idea if MSI is supported or not. You are aware of the errata > list for PCI-e on Tegra though, right? You might want to consider the > implications of said problems before you decide to use PCI-e on a > product. Yes, I am aware of it. The problems shouldn't be show-stoppers, though. > On more MSI details; I suggest you try to get access to internal > information through your Nvidia FAE -- I don't have any more > information on it than you do but if I wanted to find out that is the > route I would take myself. I did that and our FAE is now trying to make documentation available regarding the AFI controller and MSI initialization. Thanks, Thierry
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