Re: [PATCH net-next] net: dsa: lan9303: Introduce lan9303_read_wait

From: Vivien Didelot
Date: Tue Dec 12 2017 - 13:08:33 EST


Hi Egil,

Egil Hjelmeland <privat@xxxxxxxxxxxxxxxxxx> writes:

> Simplify lan9303_indirect_phy_wait_for_completion()
> and lan9303_switch_wait_for_completion() by using a new function
> lan9303_read_wait()
>
> Signed-off-by: Egil Hjelmeland <privat@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/net/dsa/lan9303-core.c | 59 +++++++++++++++++++-----------------------
> 1 file changed, 27 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
> index c1b004fa64d9..96ccce0939d3 100644
> --- a/drivers/net/dsa/lan9303-core.c
> +++ b/drivers/net/dsa/lan9303-core.c
> @@ -249,6 +249,29 @@ static int lan9303_read(struct regmap *regmap, unsigned int offset, u32 *reg)
> return -EIO;
> }
>
> +/* Wait a while until mask & reg == value. Otherwise return timeout. */
> +static int lan9303_read_wait(struct lan9303 *chip, int offset, int mask,
> + char value)
> +{
> + int i;
> +
> + for (i = 0; i < 25; i++) {
> + u32 reg;
> + int ret;
> +
> + ret = lan9303_read(chip->regmap, offset, &reg);
> + if (ret) {
> + dev_err(chip->dev, "%s failed to read offset %d: %d\n",
> + __func__, offset, ret);
> + return ret;
> + }
> + if ((reg & mask) == value)
> + return 0;

That is weird to mix int, u32 and char for mask checking. I suggest you
to use the u32 type as well for both mask and value.

Looking at how lan9303_read_wait is called, the value argument doesn't
seem necessary. You can directly return 0 if (!(reg & mask)).

> + usleep_range(1000, 2000);
> + }
> + return -ETIMEDOUT;

A newline before the return statment would be appreciated.

> +}
> +
> static int lan9303_virt_phy_reg_read(struct lan9303 *chip, int regnum)
> {
> int ret;
> @@ -274,22 +297,8 @@ static int lan9303_virt_phy_reg_write(struct lan9303 *chip, int regnum, u16 val)
>
> static int lan9303_indirect_phy_wait_for_completion(struct lan9303 *chip)
> {
> - int ret, i;
> - u32 reg;
> -
> - for (i = 0; i < 25; i++) {
> - ret = lan9303_read(chip->regmap, LAN9303_PMI_ACCESS, &reg);
> - if (ret) {
> - dev_err(chip->dev,
> - "Failed to read pmi access status: %d\n", ret);
> - return ret;
> - }
> - if (!(reg & LAN9303_PMI_ACCESS_MII_BUSY))
> - return 0;
> - usleep_range(1000, 2000);
> - }
> -
> - return -EIO;
> + return lan9303_read_wait(chip, LAN9303_PMI_ACCESS,
> + LAN9303_PMI_ACCESS_MII_BUSY, 0);
> }
>
> static int lan9303_indirect_phy_read(struct lan9303 *chip, int addr, int regnum)
> @@ -366,22 +375,8 @@ EXPORT_SYMBOL_GPL(lan9303_indirect_phy_ops);
>
> static int lan9303_switch_wait_for_completion(struct lan9303 *chip)
> {
> - int ret, i;
> - u32 reg;
> -
> - for (i = 0; i < 25; i++) {
> - ret = lan9303_read(chip->regmap, LAN9303_SWITCH_CSR_CMD, &reg);
> - if (ret) {
> - dev_err(chip->dev,
> - "Failed to read csr command status: %d\n", ret);
> - return ret;
> - }
> - if (!(reg & LAN9303_SWITCH_CSR_CMD_BUSY))
> - return 0;
> - usleep_range(1000, 2000);
> - }
> -
> - return -EIO;
> + return lan9303_read_wait(chip, LAN9303_SWITCH_CSR_CMD,
> + LAN9303_SWITCH_CSR_CMD_BUSY, 0);
> }
>
> static int lan9303_write_switch_reg(struct lan9303 *chip, u16 regnum, u32 val)


Thanks,

Vivien