[PATCH 03/15] cxl: Enable bus mastering for devices using CAPP DMA mode

Ian Munsie imunsie at au1.ibm.com
Thu Jul 14 07:17:02 AEST 2016


From: Ian Munsie <imunsie at au1.ibm.com>

Devices that use CAPP DMA mode (such as the Mellanox CX4) require bus
master to be enabled in order for the CAPI traffic to flow. This should
be harmless to enable for other cxl devices, so unconditionally enable
it in the adapter init flow.

Signed-off-by: Ian Munsie <imunsie at au1.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat at linux.vnet.ibm.com>
---
 drivers/misc/cxl/pci.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 6ac6b05..deef9c7 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1264,6 +1264,9 @@ static int cxl_configure_adapter(struct cxl *adapter, struct pci_dev *dev)
 	if ((rc = adapter->native->sl_ops->adapter_regs_init(adapter, dev)))
 		goto err;
 
+	/* Required for devices using CAPP DMA mode, harmless for others */
+	pci_set_master(dev);
+
 	if ((rc = pnv_phb_to_cxl_mode(dev, adapter->native->sl_ops->capi_mode)))
 		goto err;
 
-- 
2.8.1



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