lede/target/linux/ipq807x/patches-5.10/154-drivers-thermal-tsens-add-timeout-to-get_tem_tsens_v.patch
2021-06-24 12:16:06 +08:00

56 lines
1.7 KiB
Diff

From 47b165aa6ed3b85b793c5bfb27050c93a194c0cc Mon Sep 17 00:00:00 2001
From: Ansuel Smith <ansuelsmth@gmail.com>
Date: Wed, 19 May 2021 00:52:21 +0200
Subject: [PATCH 2/2] drivers: thermal: tsens: add timeout to
get_tem_tsens_valid
The function can loop and lock the system if for whatever reason the bit
for the target sensor is NEVER valid. This is the case if a sensor is
disabled by the factory and the valid bit is never reported as actually
valid. Add a timeout check and exit if a timeout occurs. As this is
a very rare condition, handle the timeout only if the first read fails.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
drivers/thermal/qcom/tsens.c | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)
--- a/drivers/thermal/qcom/tsens.c
+++ b/drivers/thermal/qcom/tsens.c
@@ -587,19 +587,28 @@ int get_temp_tsens_valid(const struct ts
int hw_id = s->hw_id;
u32 temp_idx = LAST_TEMP_0 + hw_id;
u32 valid_idx = VALID_0 + hw_id;
+ unsigned long timeout;
u32 valid;
int ret;
ret = regmap_field_read(priv->rf[valid_idx], &valid);
if (ret)
return ret;
- while (!valid) {
- /* Valid bit is 0 for 6 AHB clock cycles.
- * At 19.2MHz, 1 AHB clock is ~60ns.
- * We should enter this loop very, very rarely.
- */
- ndelay(400);
- ret = regmap_field_read(priv->rf[valid_idx], &valid);
+
+ if (!valid) {
+ timeout = jiffies + msecs_to_jiffies(20);
+
+ do {
+ /* Valid bit is 0 for 6 AHB clock cycles.
+ * At 19.2MHz, 1 AHB clock is ~60ns.
+ * We should enter this loop very, very rarely.
+ */
+ ndelay(400);
+ ret = regmap_field_read(priv->rf[valid_idx], &valid);
+ if (valid || ret)
+ break;
+ } while (!(ret = time_after_eq(jiffies, timeout)));
+
if (ret)
return ret;
}