Re: [PATCH RESEND 4/4] mfd: arizona: Use regmap_read_poll_timeout instead of hard coding it

From: Lee Jones
Date: Tue Mar 14 2017 - 13:07:18 EST


On Thu, 09 Mar 2017, Charles Keepax wrote:

> arizona_poll_reg essentially hard-codes regmap_read_poll_timeout, this
> patch updates the implementation to use regmap_read_poll_timeout. We
> still keep arizona_poll_reg around as regmap_read_poll_timeout is a
> macro so rather than expand this for each caller keep it wrapped in
> arizona_poll_reg.
>
> Whilst we are doing this make the timeouts a little more generous as the
> previous system had a bit more slack as it was done as a delay per
> iteration of the loop whereas regmap_read_poll_timeout compares ktime's.
>
> Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/mfd/arizona-core.c | 38 ++++++++++++++------------------------
> 1 file changed, 14 insertions(+), 24 deletions(-)

Apart from patch count, is there any technical reason why this patch
shouldn't just be rolled into patch 3?

> diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
> index 09d48ed..75488e6 100644
> --- a/drivers/mfd/arizona-core.c
> +++ b/drivers/mfd/arizona-core.c
> @@ -235,35 +235,25 @@ static irqreturn_t arizona_overclocked(int irq, void *data)
> return IRQ_HANDLED;
> }
>
> -#define ARIZONA_REG_POLL_DELAY_MS 5
> -#define ARIZONA_REG_POLL_DELAY_US (ARIZONA_REG_POLL_DELAY_MS * 1000)
> +#define ARIZONA_REG_POLL_DELAY_US 7500
>
> static int arizona_poll_reg(struct arizona *arizona,
> int timeout_ms, unsigned int reg,
> unsigned int mask, unsigned int target)
> {
> - unsigned int npolls = (timeout_ms + ARIZONA_REG_POLL_DELAY_MS - 1) /
> - ARIZONA_REG_POLL_DELAY_MS;
> unsigned int val = 0;
> - int ret, i;
> -
> - for (i = 0; i < npolls; i++) {
> - ret = regmap_read(arizona->regmap, reg, &val);
> - if (ret != 0) {
> - dev_err(arizona->dev, "Failed to read reg 0x%x: %d\n",
> - reg, ret);
> - continue;
> - }
> -
> - if ((val & mask) == target)
> - return 0;
> + int ret;
>
> - usleep_range(ARIZONA_REG_POLL_DELAY_US,
> - ARIZONA_REG_POLL_DELAY_US * 2);
> - }
> + ret = regmap_read_poll_timeout(arizona->regmap,
> + ARIZONA_INTERRUPT_RAW_STATUS_5, val,
> + ((val & mask) == target),
> + ARIZONA_REG_POLL_DELAY_US,
> + timeout_ms * 1000);
> + if (ret)
> + dev_err(arizona->dev, "Polling reg 0x%x timed out: %x\n",
> + reg, val);
>
> - dev_err(arizona->dev, "Polling reg 0x%x timed out: %x\n", reg, val);
> - return -ETIMEDOUT;
> + return ret;
> }
>
> static int arizona_wait_for_boot(struct arizona *arizona)
> @@ -275,7 +265,7 @@ static int arizona_wait_for_boot(struct arizona *arizona)
> * we won't race with the interrupt handler as it'll be blocked on
> * runtime resume.
> */
> - ret = arizona_poll_reg(arizona, 25, ARIZONA_INTERRUPT_RAW_STATUS_5,
> + ret = arizona_poll_reg(arizona, 30, ARIZONA_INTERRUPT_RAW_STATUS_5,
> ARIZONA_BOOT_DONE_STS, ARIZONA_BOOT_DONE_STS);
>
> if (!ret)
> @@ -345,7 +335,7 @@ static int arizona_enable_freerun_sysclk(struct arizona *arizona,
> ret);
> return ret;
> }
> - ret = arizona_poll_reg(arizona, 125, ARIZONA_INTERRUPT_RAW_STATUS_5,
> + ret = arizona_poll_reg(arizona, 180, ARIZONA_INTERRUPT_RAW_STATUS_5,
> ARIZONA_FLL1_CLOCK_OK_STS,
> ARIZONA_FLL1_CLOCK_OK_STS);
> if (ret)
> @@ -409,7 +399,7 @@ static int wm5102_apply_hardware_patch(struct arizona *arizona)
> goto err;
> }
>
> - ret = arizona_poll_reg(arizona, 25, ARIZONA_WRITE_SEQUENCER_CTRL_1,
> + ret = arizona_poll_reg(arizona, 30, ARIZONA_WRITE_SEQUENCER_CTRL_1,
> ARIZONA_WSEQ_BUSY, 0);
> if (ret)
> regmap_write(arizona->regmap, ARIZONA_WRITE_SEQUENCER_CTRL_0,

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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