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authorNick Hu <nickhu@andestech.com>2019-05-30 10:01:17 +0300
committerPaul Walmsley <paul.walmsley@sifive.com>2019-06-11 18:04:26 +0300
commitd0e1f2110a5eeb6e410b2dd37d98bc5b30da7bc7 (patch)
tree9bfb7c63d1ea6a48b48a6bd222dc472835abf261 /arch/riscv/lib
parent405945588feedac8d7609113de9c62e72575a0ef (diff)
downloadlinux-d0e1f2110a5eeb6e410b2dd37d98bc5b30da7bc7.tar.xz
riscv: Fix udelay in RV32.
In RV32, udelay would delay the wrong cycle. When it shifts right "UDELAY_SHIFT" bits, it either delays 0 cycle or 1 cycle. It only works correctly in RV64. Because the 'ucycles' always needs to be 64 bits variable. Signed-off-by: Nick Hu <nickhu@andestech.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> [paul.walmsley@sifive.com: fixed minor spelling error] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Diffstat (limited to 'arch/riscv/lib')
-rw-r--r--arch/riscv/lib/delay.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/riscv/lib/delay.c b/arch/riscv/lib/delay.c
index dce8ae24c6d3..ee6853c1e341 100644
--- a/arch/riscv/lib/delay.c
+++ b/arch/riscv/lib/delay.c
@@ -88,7 +88,7 @@ EXPORT_SYMBOL(__delay);
void udelay(unsigned long usecs)
{
- unsigned long ucycles = usecs * lpj_fine * UDELAY_MULT;
+ u64 ucycles = (u64)usecs * lpj_fine * UDELAY_MULT;
if (unlikely(usecs > MAX_UDELAY_US)) {
__delay((u64)usecs * riscv_timebase / 1000000ULL);