Re: 2.6.37-git17 virtual IO boot failure
From: Nishanth Aravamudan <hidden>
Date: 2011-01-19 00:48:36
On 18.01.2011 [14:47:18 -0800], Nishanth Aravamudan wrote:
quoted hunk ↗ jump to hunk
On 18.01.2011 [12:31:52 +1100], Anton Blanchard wrote:quoted
Hi, I was testing 2.6.37-git17 on a POWER7 with virtual IO and hit this: Trying to unpack rootfs image as initramfs... Freeing initrd memory: 7446k freed vio 30000000: Warning: IOMMU dma not supported: mask 0xffffffffffffffff, table unavailable vio 4000: Warning: IOMMU dma not supported: mask 0xffffffffffffffff, table unavailable vio 4001: Warning: IOMMU dma not supported: mask 0xffffffffffffffff, table unavailable vio 4002: Warning: IOMMU dma not supported: mask 0xffffffffffffffff, table unavailable vio 4004: Warning: IOMMU dma not supported: mask 0xffffffffffffffff, table unavailable audit: initializing netlink socket (disabled) Haven't had a chance to look closer yet.After debugging a bit, this would appear to be due to the second hunk of b3c73856ae47d43d0d181f9de1c1c6c0820c4515.diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c index b265405..1b695fd 100644 --- a/arch/powerpc/kernel/vio.c +++ b/arch/powerpc/kernel/vio.c@@ -1257,6 +1257,10 @@ struct vio_dev *vio_register_device_node(struct device_node *of_node) viodev->dev.parent = &vio_bus_device.dev; viodev->dev.bus = &vio_bus_type; viodev->dev.release = vio_dev_release; + /* needed to ensure proper operation of coherent allocations + * later, in case driver doesn't set it explicitly */ + dma_set_mask(&viodev->dev, DMA_BIT_MASK(64)); + dma_set_coherent_mask(&viodev->dev, DMA_BIT_MASK(64)); /* register with generic device framework */ if (device_register(&viodev->dev)) {Milton, Sonny, any thoughts?
A bit more detail after trying a few more kernels on the box that originally showed the error: 1) This doesn't actually prevent booting, afaict. I think it "just" disables DMA, which is bad, but not a boot fail, technically. 2) Reverting the above commit definitely prevents those messages. 3) I'm seeing a separate issue with 2.6.37-git17 (that's not present in 2.6.37): sd 0:4:2:0: [sda] Aborting command: 2A sd 0:4:2:0: Abort timed out. Resetting bus. At which point the box locks up :) So testing fixes is a bit of a challenge right now. Ben, if you're ok with waiting to see if Milton or Sonny have any ideas, I'd like to hold off on asking for a revert. In the case they do, I'll be able to test and send out any proposed fix rapidly. Thanks, Nish -- Nishanth Aravamudan [off-list ref] IBM Linux Technology Center