On 06/24/2017 08:39 AM, Patrick Venture wrote:
Reduce the fan_tach period such that the fan controller uses a shorter
period to measure the rpm.
The original period of 0x1000 was chosen as a conversative value from the
reference implementation. Through experimentation on the quanta-q71l
board, I was able to drive the number down which ultimately reduced the
time the controller would use to determine the fan_tach. This value was
recently tested and accepted downstream on the IBM Zaius board which uses
the ast2500.
Future work: It may be worthwhile as this is a tunable parameter to the
system, to allow overriding it through the device tree.
Testing: Tested on an ast2400 sitting on a quanta-q71l and ast2500 on
power9.
Signed-off-by: Patrick Venture <[email protected]>
Applied, thanks.
Guenter
---
v4: Added explanation for value.
v3: Added missing change log
v2: Updated commit message language
---
drivers/hwmon/aspeed-pwm-tacho.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
index 86e2ea8287a7..b2ab5612d8a4 100644
--- a/drivers/hwmon/aspeed-pwm-tacho.c
+++ b/drivers/hwmon/aspeed-pwm-tacho.c
@@ -160,7 +160,7 @@
* 11: reserved.
*/
#define M_TACH_MODE 0x02 /* 10b */
-#define M_TACH_UNIT 0x1000
+#define M_TACH_UNIT 0x00c0
#define INIT_FAN_CTRL 0xFF
struct aspeed_pwm_tacho_data {
--
To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
