On Sun, Jul 26, 2020 at 03:00:59PM -0700, Guenter Roeck wrote:
> Since commit c5cd2b47b203 ("platform/chrome: cros_ec_proto: Report command
> not supported") we can no longer assume that cros_ec_cmd_xfer_status()
> reports -EPROTO for all errors returned by the EC itself. A follow-up
> patch will change cros_ec_cmd_xfer_status() to report additional errors
> reported by the EC as distinguished Linux error codes.
>
> Handle this change by no longer assuming that only -EPROTO is used
> to report all errors returned by the EC itself. Instead, support both
> the old and the new error codes.
>
> Cc: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
> Cc: Yu-Hsuan Hsu <yuhsuan@xxxxxxxxxxxx>
> Cc: Prashant Malani <pmalani@xxxxxxxxxxxx>
> Cc: Brian Norris <briannorris@xxxxxxxxxxxx>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> v3: Added patch
>
> drivers/pwm/pwm-cros-ec.c | 21 ++++++++++++++-------
> 1 file changed, 14 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
> index 09c08dee099e..ef05fba1bd37 100644
> --- a/drivers/pwm/pwm-cros-ec.c
> +++ b/drivers/pwm/pwm-cros-ec.c
> @@ -213,20 +213,27 @@ static int cros_ec_num_pwms(struct cros_ec_device *ec)
> u32 result = 0;
>
> ret = __cros_ec_pwm_get_duty(ec, i, &result);
> - /* We want to parse EC protocol errors */
> - if (ret < 0 && !(ret == -EPROTO && result))
> - return ret;
> -
> /*
> * We look for SUCCESS, INVALID_COMMAND, or INVALID_PARAM
> * responses; everything else is treated as an error.
> */
This comment is at least misleading now.
> - if (result == EC_RES_INVALID_COMMAND)
> + switch (ret) {
> + case -EOPNOTSUPP: /* invalid command */
> return -ENODEV;
My first reaction here was to wonder why -EOPNOTSUPP isn't passed to the
upper layer. OK, this is a loop to test the number of available devices.
> - else if (result == EC_RES_INVALID_PARAM)
> + case -EINVAL: /* invalid parameter */
> return i;
> - else if (result)
> + case -EPROTO:
> + /* Old or new error return code: Handle both */
> + if (result == EC_RES_INVALID_COMMAND)
> + return -ENODEV;
> + else if (result == EC_RES_INVALID_PARAM)
> + return i;
If I understand correctly this surprising calling convention (output
parameter is filled even though the function returned an error) is the
old one that is to be fixed.
> return -EPROTO;
> + default:
> + if (ret < 0)
> + return ret;
> + break;
> + }
> }
>
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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