[PATCH 1/2] powerpc/eeh: Enable PCI_COMMAND_MASTER for PCI bridges
From: Gavin Shan <hidden>
Date: 2013-11-12 06:49:34
Subsystem:
linux for powerpc (32-bit and 64-bit), pci enhanced error handling (eeh) for powerpc, the rest · Maintainers:
Madhavan Srinivasan, Mahesh J Salgaonkar, Linus Torvalds
On PHB3, we will fail to fetch IODA tables without PCI_COMMAND_MASTER on PCI bridges. According to one experiment I had, the MSIx interrupts didn't raise from the adapter without the bit applied to all upstream PCI bridges including root port of the adapter. The patch forces to have that bit enabled accordingly. Signed-off-by: Gavin Shan <redacted> --- arch/powerpc/kernel/eeh.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 1fb331d..180af13 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c@@ -687,6 +687,15 @@ void eeh_save_bars(struct eeh_dev *edev) for (i = 0; i < 16; i++) eeh_ops->read_config(dn, i * 4, 4, &edev->config_space[i]); + + /* + * For PCI bridges including root port, we need enable bus + * master explicitly. Otherwise, it can't fetch IODA table + * entries correctly. So we cache the bit in advance so that + * we can restore it after reset, either PHB range or PE range. + */ + if (edev->mode & EEH_DEV_BRIDGE) + edev->config_space[1] |= PCI_COMMAND_MASTER; } /**
--
1.7.9.5