openwrtv3/target/linux/cns3xxx/patches-4.4/130-Extend-PCIE_BUS_PEER2PEER-to-set-MRSS-128-to-fix-CNS3xxx-BM-DMA..patch
John Crispin 687ab51fb2 cns3xxx: set both MPS 'and' MRSS to 128
Fixes some DMA issues with this platform. Because this isn't currently accepted,
and can potentially disrupt other platforms (as read in commit log), I will
leave this cns3xxx specific.

Original Patch: https://patchwork.ozlabs.org/patch/600024/

Signed-off-by: Pushpal Sidhu <psidhu@gateworks.com>

SVN-Revision: 49249
2016-04-26 11:44:00 +00:00

23 lines
958 B
Diff

--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1924,7 +1924,8 @@ static void pcie_write_mrrs(struct pci_d
/* In the "safe" case, do not configure the MRRS. There appear to be
* issues with setting MRRS to 0 on a number of devices.
*/
- if (pcie_bus_config != PCIE_BUS_PERFORMANCE)
+ if (pcie_bus_config != PCIE_BUS_PERFORMANCE &&
+ pcie_bus_config != PCIE_BUS_PEER2PEER)
return;
/* For Max performance, the MRRS must be set to the largest supported
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -756,7 +756,7 @@ enum pcie_bus_config_types {
PCIE_BUS_DEFAULT, /* ensure MPS matches upstream bridge */
PCIE_BUS_SAFE, /* use largest MPS boot-time devices support */
PCIE_BUS_PERFORMANCE, /* use MPS and MRRS for best performance */
- PCIE_BUS_PEER2PEER, /* set MPS = 128 for all devices */
+ PCIE_BUS_PEER2PEER, /* set MPS and MRSS to 128 for all devices */
};
extern enum pcie_bus_config_types pcie_bus_config;