summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorAndrew Donnellan <andrew.donnellan@au1.ibm.com>2016-07-22 10:16:35 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2017-05-03 07:45:37 +0300
commitb7da1230532984fc00962b2c8be94acc87655707 (patch)
treed4f8575404764758a852ae8b11ec0cf6493c00d9 /arch
parentc0b64978f09195e00d6649ca0ad0242a80e6e99a (diff)
downloadlinux-b7da1230532984fc00962b2c8be94acc87655707.tar.xz
powerpc/powernv: Document cxl dependency on special case in pnv_eeh_reset()
pnv_eeh_reset() has special handling for PEs whose primary bus is the root bus or the bus immediately underneath the root port. The cxl bi-modal card support added in b0b5e5918ad1 ("cxl: Add cxl_check_and_switch_mode() API to switch bi-modal cards") relies on this behaviour when hot-resetting the CAPI adapter following a mode switch. Document this in pnv_eeh_reset() so we don't accidentally break it. Suggested-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/platforms/powernv/eeh-powernv.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 6fb5522acd70..d2f19821d71d 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
@@ -1102,6 +1102,13 @@ static int pnv_eeh_reset(struct eeh_pe *pe, int option)
return -EIO;
}
+ /*
+ * If dealing with the root bus (or the bus underneath the
+ * root port), we reset the bus underneath the root port.
+ *
+ * The cxl driver depends on this behaviour for bi-modal card
+ * switching.
+ */
if (pci_is_root_bus(bus) ||
pci_is_root_bus(bus->parent))
return pnv_eeh_root_reset(hose, option);