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| author | Nick Hu <nickhu@andestech.com> | 2019-05-30 15:01:17 +0800 |
|---|---|---|
| committer | Paul Walmsley <paul.walmsley@sifive.com> | 2019-06-11 08:04:26 -0700 |
| commit | d0e1f2110a5eeb6e410b2dd37d98bc5b30da7bc7 (patch) | |
| tree | 9bfb7c63d1ea6a48b48a6bd222dc472835abf261 /arch | |
| parent | 405945588feedac8d7609113de9c62e72575a0ef (diff) | |
| download | linux-d0e1f2110a5eeb6e410b2dd37d98bc5b30da7bc7.tar.gz | |
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')
| -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); |