From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>, linux-rtc@vger.kernel.org
Subject: [PATCH v2 2/9] powerpc/powernv: OPAL RTC driver standardise OPAL_BUSY loops
Date: Mon, 9 Apr 2018 15:24:24 +1000 [thread overview]
Message-ID: <20180409052431.26405-3-npiggin@gmail.com> (raw)
In-Reply-To: <20180409052431.26405-1-npiggin@gmail.com>
Convert to using the standard delay poll/delay form.
The OPAL RTC driver:
- Did not previously delay or sleep in the OPAL_BUSY_EVENT case.
There have been scheduling delays of up to 50 seconds observed here
(BMC reboot can do it), which this should fix.
Cc: linux-rtc@vger.kernel.org
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/platforms/powernv/opal-rtc.c | 6 +++--
drivers/rtc/rtc-opal.c | 33 ++++++++++++++---------
2 files changed, 25 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/opal-rtc.c b/arch/powerpc/platforms/powernv/opal-rtc.c
index f8868864f373..f530cf62594d 100644
--- a/arch/powerpc/platforms/powernv/opal-rtc.c
+++ b/arch/powerpc/platforms/powernv/opal-rtc.c
@@ -48,10 +48,12 @@ unsigned long __init opal_get_boot_time(void)
while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
- if (rc == OPAL_BUSY_EVENT)
+ if (rc == OPAL_BUSY_EVENT) {
+ mdelay(OPAL_BUSY_DELAY_MS);
opal_poll_events(NULL);
- else if (rc == OPAL_BUSY)
+ } else if (rc == OPAL_BUSY) {
mdelay(10);
+ }
}
if (rc != OPAL_SUCCESS)
return 0;
diff --git a/drivers/rtc/rtc-opal.c b/drivers/rtc/rtc-opal.c
index 304e891e35fc..cddcc4749d39 100644
--- a/drivers/rtc/rtc-opal.c
+++ b/drivers/rtc/rtc-opal.c
@@ -57,7 +57,7 @@ static void tm_to_opal(struct rtc_time *tm, u32 *y_m_d, u64 *h_m_s_ms)
static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm)
{
- long rc = OPAL_BUSY;
+ s64 rc = OPAL_BUSY;
int retries = 10;
u32 y_m_d;
u64 h_m_s_ms;
@@ -66,13 +66,17 @@ static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm)
while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
- if (rc == OPAL_BUSY_EVENT)
+ if (rc == OPAL_BUSY_EVENT) {
+ msleep(OPAL_BUSY_DELAY_MS);
opal_poll_events(NULL);
- else if (retries-- && (rc == OPAL_HARDWARE
- || rc == OPAL_INTERNAL_ERROR))
+ } else if (rc == OPAL_BUSY) {
msleep(10);
- else if (rc != OPAL_BUSY && rc != OPAL_BUSY_EVENT)
- break;
+ } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) {
+ if (retries--) {
+ msleep(10); /* Wait 10ms before retry */
+ rc = OPAL_BUSY; /* go around again */
+ }
+ }
}
if (rc != OPAL_SUCCESS)
@@ -87,21 +91,26 @@ static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm)
static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm)
{
- long rc = OPAL_BUSY;
+ s64 rc = OPAL_BUSY;
int retries = 10;
u32 y_m_d = 0;
u64 h_m_s_ms = 0;
tm_to_opal(tm, &y_m_d, &h_m_s_ms);
+
while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
rc = opal_rtc_write(y_m_d, h_m_s_ms);
- if (rc == OPAL_BUSY_EVENT)
+ if (rc == OPAL_BUSY_EVENT) {
+ msleep(OPAL_BUSY_DELAY_MS);
opal_poll_events(NULL);
- else if (retries-- && (rc == OPAL_HARDWARE
- || rc == OPAL_INTERNAL_ERROR))
+ } else if (rc == OPAL_BUSY) {
msleep(10);
- else if (rc != OPAL_BUSY && rc != OPAL_BUSY_EVENT)
- break;
+ } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) {
+ if (retries--) {
+ msleep(10); /* Wait 10ms before retry */
+ rc = OPAL_BUSY; /* go around again */
+ }
+ }
}
return rc == OPAL_SUCCESS ? 0 : -EIO;
--
2.17.0
next prev parent reply other threads:[~2018-04-09 5:25 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-09 5:24 [PATCH v2 0/9] first step of standardising OPAL_BUSY handling Nicholas Piggin
2018-04-09 5:24 ` [PATCH v2 1/9] powerpc/powernv: define a standard delay for OPAL_BUSY type retry loops Nicholas Piggin
2018-04-09 5:24 ` Nicholas Piggin [this message]
2018-04-09 5:24 ` [PATCH v2 3/9] powerpc/powernv: opal_put_chars partial write fix Nicholas Piggin
2018-04-09 5:50 ` Benjamin Herrenschmidt
2018-04-09 5:24 ` [PATCH v2 4/9] powerpc/powernv: OPAL console standardise OPAL_BUSY loops Nicholas Piggin
2018-04-09 5:53 ` Benjamin Herrenschmidt
2018-04-09 6:13 ` Nicholas Piggin
2018-04-09 8:22 ` Benjamin Herrenschmidt
2018-04-09 5:24 ` [PATCH v2 5/9] powerpc/powernv: OPAL platform " Nicholas Piggin
2018-04-09 5:24 ` [PATCH v2 6/9] powerpc/powernv: OPAL NVRAM driver standardise OPAL_BUSY delays Nicholas Piggin
2018-04-09 5:24 ` [PATCH v2 7/9] powerpc/powernv: OPAL dump support " Nicholas Piggin
2018-04-09 5:24 ` [PATCH v2 8/9] powerpc/xive: " Nicholas Piggin
2018-04-09 5:24 ` [PATCH v2 9/9] powerpc/powernv: opal-kmsg standardise OPAL_BUSY handling Nicholas Piggin
2018-04-10 5:01 ` Russell Currey
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