[openwrt/openwrt] kernel: fix MIPS GIC clock source counter width (affects MT7621)

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch master:
https://git.lede-project.org/04052051405c2835aecf9c4d539bc6ed4e05878d

commit 04052051405c2835aecf9c4d539bc6ed4e05878d
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Wed Feb 21 13:54:35 2018 +0100

    kernel: fix MIPS GIC clock source counter width (affects MT7621)
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 ...-mips-gic-timer-fix-clocksource-counter-w.patch | 23 ++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/target/linux/generic/pending-4.14/101-clocksource-mips-gic-timer-fix-clocksource-counter-w.patch b/target/linux/generic/pending-4.14/101-clocksource-mips-gic-timer-fix-clocksource-counter-w.patch
new file mode 100644
index 0000000..a554aa1
--- /dev/null
+++ b/target/linux/generic/pending-4.14/101-clocksource-mips-gic-timer-fix-clocksource-counter-w.patch
@@ -0,0 +1,23 @@
+From: Felix Fietkau <nbd at nbd.name>
+Date: Wed, 21 Feb 2018 13:40:12 +0100
+Subject: [PATCH] clocksource: mips-gic-timer: fix clocksource counter width
+
+This code needs to use ffs instead of fls on the mask to determine the
+shift for reading the GIC_CONFIG_COUNTBITS field.
+
+Fixes: e07127a077c7 ("clocksource: mips-gic-timer: Use new GIC accessor functions")
+Cc: Paul Burton <paul.burton at imgtec.com>
+Signed-off-by: Felix Fietkau <nbd at nbd.name>
+---
+
+--- a/drivers/clocksource/mips-gic-timer.c
++++ b/drivers/clocksource/mips-gic-timer.c
+@@ -164,7 +164,7 @@ static int __init __gic_clocksource_init
+ 
+ 	/* Set clocksource mask. */
+ 	count_width = read_gic_config() & GIC_CONFIG_COUNTBITS;
+-	count_width >>= __fls(GIC_CONFIG_COUNTBITS);
++	count_width >>= __ffs(GIC_CONFIG_COUNTBITS);
+ 	count_width *= 4;
+ 	count_width += 32;
+ 	gic_clocksource.mask = CLOCKSOURCE_MASK(count_width);