From: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Date: Wed, 24 Feb 2016 17:27:51 +0000 (+0100)
Subject: cxl: Fix PSL timebase synchronization detection
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=923adb1646d5ba739d2a1e63ee20d60574d9da8e;p=linux-beck.git

cxl: Fix PSL timebase synchronization detection

The PSL timebase synchronization is seemingly failing for
configuration not including VIRT_CPU_ACCOUNTING_NATIVE. The driver
shows the following trace in dmesg:
PSL: Timebase sync: giving up!

The PSL timebase register is actually syncing correctly, but the cxl
driver is not detecting it. Fix is to use the proper timebase-to-time
conversion.

Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> # 4.3+
Acked-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---

diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 4c1903f781fc..0c6c17a1c59e 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -415,7 +415,7 @@ static int cxl_setup_psl_timebase(struct cxl *adapter, struct pci_dev *dev)
 		delta = mftb() - psl_tb;
 		if (delta < 0)
 			delta = -delta;
-	} while (cputime_to_usecs(delta) > 16);
+	} while (tb_to_ns(delta) > 16000);
 
 	return 0;
 }