From: Judith Mendez jm@ti.com
stable inclusion from stable-v6.6.34 commit 8b732150f2e37f6ef252db08a2df7d219b07a59c category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAD6H2
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit cae58516534e110f4a8558d48aa4435e15519121 upstream.
On AM62x, the watchdog is pet before the valid window is open. Fix min_hw_heartbeat and accommodate a 2% + static offset safety margin. The static offset accounts for max hardware error.
Remove the hack in the driver which shifts the open window boundary, since it is no longer necessary due to the fix mentioned above.
cc: stable@vger.kernel.org Fixes: 5527483f8f7c ("watchdog: rti-wdt: attach to running watchdog during probe") Signed-off-by: Judith Mendez jm@ti.com Reviewed-by: Guenter Roeck linux@roeck-us.net Link: https://lore.kernel.org/r/20240417205700.3947408-1-jm@ti.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Wim Van Sebroeck wim@linux-watchdog.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Wang Hai wanghai38@huawei.com --- drivers/watchdog/rti_wdt.c | 34 +++++++++++++++------------------- 1 file changed, 15 insertions(+), 19 deletions(-)
diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index 9215793a1c81..4895a69015a8 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -59,6 +59,8 @@ #define PON_REASON_EOF_NUM 0xCCCCBBBB #define RESERVED_MEM_MIN_SIZE 12
+#define MAX_HW_ERROR 250 + static int heartbeat = DEFAULT_HEARTBEAT;
/* @@ -97,7 +99,7 @@ static int rti_wdt_start(struct watchdog_device *wdd) * to be 50% or less than that; we obviouly want to configure the open * window as large as possible so we select the 50% option. */ - wdd->min_hw_heartbeat_ms = 500 * wdd->timeout; + wdd->min_hw_heartbeat_ms = 520 * wdd->timeout + MAX_HW_ERROR;
/* Generate NMI when wdt expires */ writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL); @@ -131,31 +133,33 @@ static int rti_wdt_setup_hw_hb(struct watchdog_device *wdd, u32 wsize) * be petted during the open window; not too early or not too late. * The HW configuration options only allow for the open window size * to be 50% or less than that. + * To avoid any glitches, we accommodate 2% + max hardware error + * safety margin. */ switch (wsize) { case RTIWWDSIZE_50P: - /* 50% open window => 50% min heartbeat */ - wdd->min_hw_heartbeat_ms = 500 * heartbeat; + /* 50% open window => 52% min heartbeat */ + wdd->min_hw_heartbeat_ms = 520 * heartbeat + MAX_HW_ERROR; break;
case RTIWWDSIZE_25P: - /* 25% open window => 75% min heartbeat */ - wdd->min_hw_heartbeat_ms = 750 * heartbeat; + /* 25% open window => 77% min heartbeat */ + wdd->min_hw_heartbeat_ms = 770 * heartbeat + MAX_HW_ERROR; break;
case RTIWWDSIZE_12P5: - /* 12.5% open window => 87.5% min heartbeat */ - wdd->min_hw_heartbeat_ms = 875 * heartbeat; + /* 12.5% open window => 89.5% min heartbeat */ + wdd->min_hw_heartbeat_ms = 895 * heartbeat + MAX_HW_ERROR; break;
case RTIWWDSIZE_6P25: - /* 6.5% open window => 93.5% min heartbeat */ - wdd->min_hw_heartbeat_ms = 935 * heartbeat; + /* 6.5% open window => 95.5% min heartbeat */ + wdd->min_hw_heartbeat_ms = 955 * heartbeat + MAX_HW_ERROR; break;
case RTIWWDSIZE_3P125: - /* 3.125% open window => 96.9% min heartbeat */ - wdd->min_hw_heartbeat_ms = 969 * heartbeat; + /* 3.125% open window => 98.9% min heartbeat */ + wdd->min_hw_heartbeat_ms = 989 * heartbeat + MAX_HW_ERROR; break;
default: @@ -233,14 +237,6 @@ static int rti_wdt_probe(struct platform_device *pdev) return -EINVAL; }
- /* - * If watchdog is running at 32k clock, it is not accurate. - * Adjust frequency down in this case so that we don't pet - * the watchdog too often. - */ - if (wdt->freq < 32768) - wdt->freq = wdt->freq * 9 / 10; - pm_runtime_enable(dev); ret = pm_runtime_resume_and_get(dev); if (ret < 0) {