diff options
| author | Nick Hu <nickhu@andestech.com> | 2019-05-30 10:01:17 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-14 09:09:40 +0300 |
| commit | 82045b8cbcc68e3f8d38e89a0ff48fc99178c2be (patch) | |
| tree | de9397bcd96e94dd81d9757a3c5c972ab5d4cfdd | |
| parent | 1ef49d30eb2d24b190fa575bf8e6f35ae622694f (diff) | |
| download | linux-82045b8cbcc68e3f8d38e89a0ff48fc99178c2be.tar.xz | |
riscv: Fix udelay in RV32.
[ Upstream commit d0e1f2110a5eeb6e410b2dd37d98bc5b30da7bc7 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/riscv/lib/delay.c | 2 |
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); |