On Thu, 27 Sep 2018 at 01:58, Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx> wrote:
>
> This commit adds reading code of the 'aspeed,timeout' DT property
> to set 'timeout' value in adapter configuration. This value still
> case be configured through an I2C_TIMEOUT ioctl on cdev too.
>
> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-aspeed.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
> index 8dc9161ced38..0d934ce0c028 100644
> --- a/drivers/i2c/busses/i2c-aspeed.c
> +++ b/drivers/i2c/busses/i2c-aspeed.c
> @@ -115,6 +115,9 @@
> /* 0x18 : I2CD Slave Device Address Register */
> #define ASPEED_I2CD_DEV_ADDR_MASK GENMASK(6, 0)
>
> +/* Timeout */
> +#define ASPEED_I2C_BUS_TIMEOUT_US_DEFAULT (5 * 1000 * 1000)
The 5 seconds time out is way too long. On a system that doesn't have
functional i2c, this holds up boot for a long time as most i2c client
drivers try to initialise their device and fail. I realise you're not
changing the value, but we should pick a better default. 1 second?
Half a second?
> +
> enum aspeed_i2c_master_state {
> ASPEED_I2C_MASTER_INACTIVE,
> ASPEED_I2C_MASTER_START,
> @@ -885,6 +888,7 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
> struct clk *parent_clk;
> struct resource *res;
> int irq, ret;
> + u32 timeout_us;
>
> bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
> if (!bus)
> @@ -918,6 +922,11 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
> bus->bus_frequency = 100000;
> }
>
> + ret = of_property_read_u32(pdev->dev.of_node, "aspeed,timeout",
> + &timeout_us);
Can we make this binding generic? It's not specific to aspeed's
hardware. Getting the value could even part of the i2c core.
I read the previous thread with Wolfram. I think this would still fit
with what Wolfram suggested, but please forgive my jetlagged brain if
I've missed something.
Cheers,
Joel
> + if (ret)
> + timeout_us = ASPEED_I2C_BUS_TIMEOUT_US_DEFAULT;
> +
> match = of_match_node(aspeed_i2c_bus_of_table, pdev->dev.of_node);
> if (!match)
> bus->get_clk_reg_val = aspeed_i2c_24xx_get_clk_reg_val;
> @@ -930,7 +939,7 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
> init_completion(&bus->cmd_complete);
> bus->adap.owner = THIS_MODULE;
> bus->adap.retries = 0;
> - bus->adap.timeout = 5 * HZ;
> + bus->adap.timeout = usecs_to_jiffies(timeout_us);
> bus->adap.algo = &aspeed_i2c_algo;
> bus->adap.dev.parent = &pdev->dev;
> bus->adap.dev.of_node = pdev->dev.of_node;
> --
> 2.19.0
>
