kernel: 5.10: fix busy wait loop in mediatek PPE code

Reapply changes added to 5.4 but not copied to 5.10:
3da4acaa7b ("kernel: fix busy wait loop in mediatek PPE code")

The intention is for the loop to timeout if the body does not succeed.
The current logic calls time_is_before_jiffies(timeout) which is false
until after the timeout, so the loop body never executes.

time_is_after_jiffies(timeout) will return true until timeout is less
than jiffies, which is the intended behavior here.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
This commit is contained in:
Adrian Schmutzler 2021-02-16 23:16:00 +01:00
parent 0e407dfe8b
commit 99f2b464b4

View File

@ -185,7 +185,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
+{ +{
+ unsigned long timeout = jiffies + HZ; + unsigned long timeout = jiffies + HZ;
+ +
+ while (time_is_before_jiffies(timeout)) { + while (time_is_after_jiffies(timeout)) {
+ if (!(ppe_r32(ppe, MTK_PPE_GLO_CFG) & MTK_PPE_GLO_CFG_BUSY)) + if (!(ppe_r32(ppe, MTK_PPE_GLO_CFG) & MTK_PPE_GLO_CFG_BUSY))
+ return 0; + return 0;
+ +