diff mbox

[Wily,SRU,v2] cxl: Fix PSL timebase synchronization detection

Message ID 1456763890-5142-1-git-send-email-tim.gardner@canonical.com
State New
Headers show

Commit Message

Tim Gardner Feb. 29, 2016, 4:38 p.m. UTC 
From: Frederic Barrat <fbarrat@linux.vnet.ibm.com>

BugLink: http://bugs.launchpad.net/bugs/1532914

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>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git commit 923adb1646d5ba739d2a1e63ee20d60574d9da8e)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
 drivers/misc/cxl/pci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Andy Whitcroft March 1, 2016, 2:04 p.m. UTC | #1 
On Mon, Feb 29, 2016 at 09:38:10AM -0700, tim.gardner@canonical.com wrote:
> From: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/1532914
> 
> 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>
> (cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git commit 923adb1646d5ba739d2a1e63ee20d60574d9da8e)

Patch looks ok, but this is an odd form.  We normally do something more
like:

(cherry picked from commit NNNN git://)

there are scripts which need to read these sadly.

> Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
> ---
>  drivers/misc/cxl/pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
> index 4c1903f..0c6c17a1 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;
>  }

Looks sane.  I am assuming v2 is adding provenance and not a code
change, as I cannot see a difference.

Acked-by: Andy Whitcroft <apw@canonical.com>

-apw
Kamal Mostafa March 3, 2016, 4:45 p.m. UTC | #2
diff mbox

Patch

diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 4c1903f..0c6c17a1 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;
 }