Commit b7da1230 authored Jul 22, 2016 by Andrew Donnellan Committed by Michael Ellerman May 03, 2017

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 b0b5e591 ("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>

parent c0b64978

arch/powerpc/platforms/powernv/eeh-powernv.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -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);