clk: at91: avoid sleeping early

It is not allowed to sleep to early in the boot process and this may lead
to kernel issues if the bootloader didn't prepare the slow clock and main
clock.

This results in the following error and dump stack on the AriettaG25:
   bad: scheduling from the idle thread!

Ensure it is possible to sleep, else simply have a delay.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lkml.kernel.org/r/20190920153906.20887-1-alexandre.belloni@bootlin.com
Fixes: 80eded6ce8 ("clk: at91: add slow clks driver")
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
This commit is contained in:
Alexandre Belloni
2019-09-20 17:39:06 +02:00
committed by Stephen Boyd
父節點 b234fe9558
當前提交 658fd65cf0
共有 2 個文件被更改,包括 20 次插入5 次删除

查看文件

@@ -297,7 +297,10 @@ static int clk_main_probe_frequency(struct regmap *regmap)
regmap_read(regmap, AT91_CKGR_MCFR, &mcfr);
if (mcfr & AT91_PMC_MAINRDY)
return 0;
usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT);
if (system_state < SYSTEM_RUNNING)
udelay(MAINF_LOOP_MIN_WAIT);
else
usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT);
} while (time_before(prep_time, timeout));
return -ETIMEDOUT;

查看文件

@@ -76,7 +76,10 @@ static int clk_slow_osc_prepare(struct clk_hw *hw)
writel(tmp | osc->bits->cr_osc32en, sckcr);
usleep_range(osc->startup_usec, osc->startup_usec + 1);
if (system_state < SYSTEM_RUNNING)
udelay(osc->startup_usec);
else
usleep_range(osc->startup_usec, osc->startup_usec + 1);
return 0;
}
@@ -187,7 +190,10 @@ static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
writel(readl(sckcr) | osc->bits->cr_rcen, sckcr);
usleep_range(osc->startup_usec, osc->startup_usec + 1);
if (system_state < SYSTEM_RUNNING)
udelay(osc->startup_usec);
else
usleep_range(osc->startup_usec, osc->startup_usec + 1);
return 0;
}
@@ -288,7 +294,10 @@ static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
writel(tmp, sckcr);
usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);
if (system_state < SYSTEM_RUNNING)
udelay(SLOWCK_SW_TIME_USEC);
else
usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);
return 0;
}
@@ -533,7 +542,10 @@ static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw)
return 0;
}
usleep_range(osc->startup_usec, osc->startup_usec + 1);
if (system_state < SYSTEM_RUNNING)
udelay(osc->startup_usec);
else
usleep_range(osc->startup_usec, osc->startup_usec + 1);
osc->prepared = true;
return 0;