From 46f401c4297a2232a037ad8801b6c83c90414cf7 Mon Sep 17 00:00:00 2001 From: Larry Finger Date: Thu, 9 Mar 2017 20:33:51 -0600 Subject: [PATCH] powerpc/pmac: Fix crash in dma-mapping.h with NULL dma_ops Commit 5657933dbb6e ("treewide: Move dma_ops from struct dev_archdata into struct device") introduced a crash for macio devices, an example backtrace being: kernel BUG at ./include/linux/dma-mapping.h:465! Oops: Exception in kernel mode, sig: 5 [#1] ... NIP [c031ddb0] dmam_alloc_coherent+0x74/0x140 LR [c031de70] dmam_alloc_coherent+0x134/0x140 Call Trace: dmam_alloc_coherent+0x134/0x140 (unreliable) pata_macio_port_start+0x3c/0x8c ata_host_start.part.5+0xfc/0x208 ata_host_activate+0x128/0x154 pata_macio_common_init+0x2f0/0x538 pata_macio_attach+0xd8/0x180 macio_device_probe+0x5c/0xec driver_probe_device+0x21c/0x314 __driver_attach+0xcc/0xd0 bus_for_each_dev+0x68/0xb4 bus_add_driver+0x1dc/0x244 driver_register+0x88/0x130 pata_macio_init+0x5c/0x88 do_one_initcall+0x40/0x170 kernel_init_freeable+0x134/0x1d0 kernel_init+0x18/0x110 ret_from_kernel_thread+0x5c/0x64 This was caused by the device having NULL dma_ops, triggering the BUG_ON(). Previously the device inherited its dma_ops via the assignment to dev->ofdev.dev.archdata. However after commit 5657933dbb6e the dma_ops are moved into dev->ofdev.dev, and so they need to be explicitly copied. Fixes: 5657933dbb6e ("treewide: Move dma_ops from struct dev_archdata into struct device") Signed-off-by: Larry Finger Suggested-by: Benjamin Herrenschmidt [mpe: Rewrite change log, add backtrace] Signed-off-by: Michael Ellerman --- drivers/macintosh/macio_asic.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/macintosh/macio_asic.c b/drivers/macintosh/macio_asic.c index 3f041b187033..f757cef293f8 100644 --- a/drivers/macintosh/macio_asic.c +++ b/drivers/macintosh/macio_asic.c @@ -392,6 +392,7 @@ static struct macio_dev * macio_add_one_device(struct macio_chip *chip, * To get all the fields, copy all archdata */ dev->ofdev.dev.archdata = chip->lbus.pdev->dev.archdata; + dev->ofdev.dev.dma_ops = chip->lbus.pdev->dev.dma_ops; #endif /* CONFIG_PCI */ #ifdef DEBUG