4.4-stable patches

added patches:
	powerpc-powernv-define-a-standard-delay-for-opal_busy-type-retry-loops.patch

diff --git a/queue-4.4/powerpc-powernv-define-a-standard-delay-for-opal_busy-type-retry-loops.patch b/queue-4.4/powerpc-powernv-define-a-standard-delay-for-opal_busy-type-retry-loops.patch
new file mode 100644 (file)
index 0000000..fff9fed
--- /dev/null
+++ b/queue-4.4/powerpc-powernv-define-a-standard-delay-for-opal_busy-type-retry-loops.patch
@@ -0,0 +1,48 @@
+From 34dd25de9fe3f60bfdb31b473bf04b28262d0896 Mon Sep 17 00:00:00 2001
+From: Nicholas Piggin <npiggin@gmail.com>
+Date: Tue, 10 Apr 2018 21:49:31 +1000
+Subject: powerpc/powernv: define a standard delay for OPAL_BUSY type retry loops
+
+From: Nicholas Piggin <npiggin@gmail.com>
+
+commit 34dd25de9fe3f60bfdb31b473bf04b28262d0896 upstream.
+
+This is the start of an effort to tidy up and standardise all the
+delays. Existing loops have a range of delay/sleep periods from 1ms
+to 20ms, and some have no delay. They all loop forever except rtc,
+which times out after 10 retries, and that uses 10ms delays. So use
+10ms as our standard delay. The OPAL maintainer agrees 10ms is a
+reasonable starting point.
+
+The idea is to use the same recipe everywhere, once this is proven to
+work then it will be documented as an OPAL API standard. Then both
+firmware and OS can agree, and if a particular call needs something
+else, then that can be documented with reasoning.
+
+This is not the end-all of this effort, it's just a relatively easy
+change that fixes some existing high latency delays. There should be
+provision for standardising timeouts and/or interruptible loops where
+possible, so non-fatal firmware errors don't cause hangs.
+
+Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
+Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
+Cc: Nathan Chancellor <natechancellor@gmail.com>
+Cc: Guenter Roeck <linux@roeck-us.net>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/powerpc/include/asm/opal.h |    3 +++
+ 1 file changed, 3 insertions(+)
+
+--- a/arch/powerpc/include/asm/opal.h
++++ b/arch/powerpc/include/asm/opal.h
+@@ -21,6 +21,9 @@
+ /* We calculate number of sg entries based on PAGE_SIZE */
+ #define SG_ENTRIES_PER_NODE ((PAGE_SIZE - 16) / sizeof(struct opal_sg_entry))
+ 
++/* Default time to sleep or delay between OPAL_BUSY/OPAL_BUSY_EVENT loops */
++#define OPAL_BUSY_DELAY_MS    10
++
+ /* /sys/firmware/opal */
+ extern struct kobject *opal_kobj;
+ 

diff --git a/queue-4.4/series b/queue-4.4/series
index a46f9e61c04dd15bce4fbb95f4f704058456dfba..b08927c851fa50af75a96b73bf201e7ffc82970b 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -39,6 +39,7 @@ usb-dwc3-pci-properly-cleanup-resource.patch
 hid-i2c-hid-fix-size-check-and-type-usage.patch
 powerpc-powernv-handle-unknown-opal-errors-in-opal_nvram_write.patch
 powerpc-64-fix-smp_wmb-barrier-definition-use-use-lwsync-consistently.patch
+powerpc-powernv-define-a-standard-delay-for-opal_busy-type-retry-loops.patch
 powerpc-powernv-fix-opal-nvram-driver-opal_busy-loops.patch
 hid-fix-hid_report_len-usage.patch
 hid-core-fix-size-as-type-u32.patch