All of lore.kernel.org
 help / color / mirror / Atom feed
From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Stewart Smith <stewart@linux.ibm.com>,
	linux-rtc@vger.kernel.org
Subject: [PATCH 2/6] powerpc/powernv: OPAL RTC driver standardise OPAL_BUSY loops
Date: Thu,  5 Apr 2018 18:15:43 +1000	[thread overview]
Message-ID: <20180405081547.13266-3-npiggin@gmail.com> (raw)
In-Reply-To: <20180405081547.13266-1-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;
-- 
2.16.3

  parent reply	other threads:[~2018-04-05  8:16 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-05  8:15 [PATCH 0/6] first step of standardising OPAL_BUSY handling Nicholas Piggin
2018-04-05  8:15 ` [PATCH 1/6] powerpc/powernv: define a standard delay for OPAL_BUSY type retry loops Nicholas Piggin
2018-04-05  8:15 ` Nicholas Piggin [this message]
2018-04-05  8:15 ` [PATCH 3/6] powerpc/powernv: OPAL platform standardise OPAL_BUSY loops Nicholas Piggin
2018-04-05  8:15 ` [PATCH 4/6] powerpc/powernv: OPAL NVRAM driver standardise OPAL_BUSY delays Nicholas Piggin
2018-04-05  8:15 ` [PATCH 5/6] powerpc/powernv: OPAL dump support " Nicholas Piggin
2018-04-05  8:15 ` [PATCH 6/6] powerpc/xive: " Nicholas Piggin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180405081547.13266-3-npiggin@gmail.com \
    --to=npiggin@gmail.com \
    --cc=benh@kernel.crashing.org \
    --cc=linux-rtc@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=stewart@linux.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.