usleep_range() is called in non-atomic context so there is little point in setting min==max the jitter of hrtimer is determined by interruptions anyway. usleep_range can only perform the intended coalescence if some room for placing the hrtimer is provided. Given the range of milliseconds the delay will be anything from 2 to a few anyway - so make it 2-5 ms. Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx> --- Problem located with an experimental coccinelle script ./drivers/staging/wilc1000/wilc_wlan.c:411:4-16: WARNING: inefficient usleep_range with range 0 (min==max) ./drivers/staging/wilc1000/wilc_wlan.c:426:4-16: WARNING: inefficient usleep_range with range 0 (min==max) Someone that knows the motivation for setting the time to 2 millisecond might need to check if the 2 milliseconds where seen as tollerable max or min - I'm assuming it was the min so extending. Patch was compile tested with: x86_64_defconfig + Staging=y, WILC1000_SDIO=m, WILC1000_SPI=m, WILC1000=m Patch is against 5.1-rc3 (localversion-next is -next-20190405) drivers/staging/wilc1000/wilc_wlan.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/staging/wilc1000/wilc_wlan.c b/drivers/staging/wilc1000/wilc_wlan.c index c238969..42da533 100644 --- a/drivers/staging/wilc1000/wilc_wlan.c +++ b/drivers/staging/wilc1000/wilc_wlan.c @@ -408,7 +408,7 @@ void chip_wakeup(struct wilc *wilc) wilc->hif_func->hif_write_reg(wilc, 1, reg & ~BIT(1)); do { - usleep_range(2 * 1000, 2 * 1000); + usleep_range(2 * 1000, 5 * 1000); wilc_get_chipid(wilc, true); } while (wilc_get_chipid(wilc, true) == 0); } while (wilc_get_chipid(wilc, true) == 0); @@ -423,7 +423,7 @@ void chip_wakeup(struct wilc *wilc) &clk_status_reg); while ((clk_status_reg & 0x1) == 0) { - usleep_range(2 * 1000, 2 * 1000); + usleep_range(2 * 1000, 5 * 1000); wilc->hif_func->hif_read_reg(wilc, 0xf1, &clk_status_reg); -- 2.1.4