From a1bd75d82c9b282507d7019608b38ba2d934946c Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 23 Apr 2018 09:07:27 +0200 Subject: [PATCH] 3.18-stable patches added patches: powerpc-powernv-define-a-standard-delay-for-opal_busy-type-retry-loops.patch --- ...delay-for-opal_busy-type-retry-loops.patch | 48 +++++++++++++++++++ queue-3.18/series | 1 + 2 files changed, 49 insertions(+) create mode 100644 queue-3.18/powerpc-powernv-define-a-standard-delay-for-opal_busy-type-retry-loops.patch diff --git a/queue-3.18/powerpc-powernv-define-a-standard-delay-for-opal_busy-type-retry-loops.patch b/queue-3.18/powerpc-powernv-define-a-standard-delay-for-opal_busy-type-retry-loops.patch new file mode 100644 index 00000000000..2d8d06ca97e --- /dev/null +++ b/queue-3.18/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 +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 + +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 +Signed-off-by: Michael Ellerman +Cc: Nathan Chancellor +Cc: Guenter Roeck +Signed-off-by: Greg Kroah-Hartman + +--- + 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 +@@ -801,6 +801,9 @@ typedef struct oppanel_line { + uint64_t line_len; + } oppanel_line_t; + ++/* 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-3.18/series b/queue-3.18/series index 159f30b7ec5..7ba8ee599ab 100644 --- a/queue-3.18/series +++ b/queue-3.18/series @@ -18,6 +18,7 @@ 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 asoc-ssm2602-replace-reg_default_raw-with-reg_default.patch thunderbolt-resume-control-channel-after-hibernation-image-is-created.patch -- 2.47.3