netdev - [PATCH net-next 02/15] bnxt_en: Disable/enable Bus master during suspend/resume.

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Date:   Sat, 23 Nov 2019 03:25:57 -0500
From:   Michael Chan <michael.chan@...adcom.com>
To:     davem@...emloft.net
Cc:     netdev@...r.kernel.org
Subject: [PATCH net-next 02/15] bnxt_en: Disable/enable Bus master during suspend/resume.

Disable Bus master during suspend to prevent DMAs after the device
goes into D3hot state.  The new 57500 devices may continue to DMA
from context memory after the system goes into D3hot state.  This
may cause some PCIe errors on some system.  Re-enable it during resume.

Signed-off-by: Michael Chan <michael.chan@...adcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 35bc579..14b6104 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -11921,6 +11921,7 @@ static int bnxt_suspend(struct device *device)
 		rc = bnxt_close(dev);
 	}
 	bnxt_hwrm_func_drv_unrgtr(bp);
+	pci_disable_device(bp->pdev);
 	rtnl_unlock();
 	return rc;
 }
@@ -11932,6 +11933,13 @@ static int bnxt_resume(struct device *device)
 	int rc = 0;

 	rtnl_lock();
+	rc = pci_enable_device(bp->pdev);
+	if (rc) {
+		netdev_err(dev, "Cannot re-enable PCI device during resume, err = %d\n",
+			   rc);
+		goto resume_exit;
+	}
+	pci_set_master(bp->pdev);
 	if (bnxt_hwrm_ver_get(bp) || bnxt_hwrm_func_drv_rgtr(bp)) {
 		rc = -ENODEV;
 		goto resume_exit;
-- 
2.5.1