Re: [PATCH v3 3/5] drm/dp: make dp_link_status and dp_get_lane_status usable from outside of the core

From: Andrzej Hajda
Date: Thu Sep 13 2018 - 07:20:40 EST


On 28.08.2018 12:24, Damian Kos wrote:
> From: Quentin Schulz <quentin.schulz@xxxxxxxxxxx>
>
> dp_link_status and dp_get_lane_status are pretty generic and can be used for
> other means, so let's make it "public".
>
> This adds drm_dp_link_status and drm_dp_get_lane_status to the header file and
> add the appropriate EXPORT_SYMBOL for it so that it can be used by other
> drivers, be they compiled built-in or as modules.

If you want to export them please document functions and their arguments.
Moreover, these functions are so tiny, so they can be defined as inline.


>
> Signed-off-by: Damian Kos <dkos@xxxxxxxxxxx>
No author sign-off.

Regards
Andrzej


> ---
> drivers/gpu/drm/drm_dp_helper.c | 20 +++++++++++---------
> include/drm/drm_dp_helper.h | 3 +++
> 2 files changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 4b5bf6ee7fa7..ee9ec2ccf878 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -43,19 +43,21 @@
> */
>
> /* Helpers for DP link training */
> -static u8 dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r)
> +u8 drm_dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r)
> {
> return link_status[r - DP_LANE0_1_STATUS];
> }
> +EXPORT_SYMBOL(drm_dp_link_status);
>
> -static u8 dp_get_lane_status(const u8 link_status[DP_LINK_STATUS_SIZE],
> +u8 drm_dp_get_lane_status(const u8 link_status[DP_LINK_STATUS_SIZE],
> int lane)
> {
> int i = DP_LANE0_1_STATUS + (lane >> 1);
> int s = (lane & 1) * 4;
> - u8 l = dp_link_status(link_status, i);
> + u8 l = drm_dp_link_status(link_status, i);
> return (l >> s) & 0xf;
> }
> +EXPORT_SYMBOL(drm_dp_get_lane_status);
>
> bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
> int lane_count)
> @@ -64,12 +66,12 @@ bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
> u8 lane_status;
> int lane;
>
> - lane_align = dp_link_status(link_status,
> - DP_LANE_ALIGN_STATUS_UPDATED);
> + lane_align = drm_dp_link_status(link_status,
> + DP_LANE_ALIGN_STATUS_UPDATED);
> if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0)
> return false;
> for (lane = 0; lane < lane_count; lane++) {
> - lane_status = dp_get_lane_status(link_status, lane);
> + lane_status = drm_dp_get_lane_status(link_status, lane);
> if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS)
> return false;
> }
> @@ -84,7 +86,7 @@ bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
> u8 lane_status;
>
> for (lane = 0; lane < lane_count; lane++) {
> - lane_status = dp_get_lane_status(link_status, lane);
> + lane_status = drm_dp_get_lane_status(link_status, lane);
> if ((lane_status & DP_LANE_CR_DONE) == 0)
> return false;
> }
> @@ -99,7 +101,7 @@ u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
> int s = ((lane & 1) ?
> DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT :
> DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT);
> - u8 l = dp_link_status(link_status, i);
> + u8 l = drm_dp_link_status(link_status, i);
>
> return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT;
> }
> @@ -112,7 +114,7 @@ u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SI
> int s = ((lane & 1) ?
> DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT :
> DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT);
> - u8 l = dp_link_status(link_status, i);
> + u8 l = drm_dp_link_status(link_status, i);
>
> return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT;
> }
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index 06a478679781..9930b2b269f2 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -952,6 +952,9 @@
> #define DP_MST_LOGICAL_PORT_0 8
>
> #define DP_LINK_STATUS_SIZE 6
> +
> +u8 drm_dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r);
> +u8 drm_dp_get_lane_status(const u8 link_status[DP_LINK_STATUS_SIZE], int lane);
> bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
> int lane_count);
> bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE],