From: Jani Nikula Date: Tue, 3 Dec 2024 15:17:08 +0000 (+0200) Subject: drm/dp: extract drm_dp_dpcd_poll_act_handled() X-Git-Tag: v6.14-rc1~174^2~18^2~9 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f2663f704d8428a7f1bacf084de460d006259f6e;p=thirdparty%2Fkernel%2Flinux.git drm/dp: extract drm_dp_dpcd_poll_act_handled() SST with 128b/132b channel coding needs this too. Extract to a separate helper, independent of MST. Pass timeout in as a parameter, anticipating that we can reduce the timeout for SST. v2: Clean up kernel-doc a bit Cc: Lyude Paul Reviewed-by: Imre Deak Reviewed-by: Lyude Paul Link: https://patchwork.freedesktop.org/patch/msgid/459fd3e96a55a8ea8ada8d27d93eaa24c235f9c1.1733238941.git.jani.nikula@intel.com Signed-off-by: Jani Nikula --- diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c index 6ee51003de3ce..fdb55c462d647 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -22,15 +22,16 @@ #include #include +#include #include #include #include +#include #include #include #include #include #include -#include #include #include @@ -779,6 +780,57 @@ int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux, } EXPORT_SYMBOL(drm_dp_dpcd_read_phy_link_status); +static int read_payload_update_status(struct drm_dp_aux *aux) +{ + int ret; + u8 status; + + ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); + if (ret < 0) + return ret; + + return status; +} + +/** + * drm_dp_dpcd_poll_act_handled() - Poll for ACT handled status + * @aux: DisplayPort AUX channel + * @timeout_ms: Timeout in ms + * + * Try waiting for the sink to finish updating its payload table by polling for + * the ACT handled bit of DP_PAYLOAD_TABLE_UPDATE_STATUS for up to @timeout_ms + * milliseconds, defaulting to 3000 ms if 0. + * + * Returns: + * 0 if the ACT was handled in time, negative error code on failure. + */ +int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms) +{ + int ret, status; + + /* default to 3 seconds, this is arbitrary */ + timeout_ms = timeout_ms ?: 3000; + + ret = readx_poll_timeout(read_payload_update_status, aux, status, + status & DP_PAYLOAD_ACT_HANDLED || status < 0, + 200, timeout_ms * USEC_PER_MSEC); + if (ret < 0 && status >= 0) { + drm_err(aux->drm_dev, "Failed to get ACT after %d ms, last status: %02x\n", + timeout_ms, status); + return -EINVAL; + } else if (status < 0) { + /* + * Failure here isn't unexpected - the hub may have + * just been unplugged + */ + drm_dbg_kms(aux->drm_dev, "Failed to read payload table status: %d\n", status); + return status; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_dpcd_poll_act_handled); + static bool is_edid_digital_input_dp(const struct drm_edid *drm_edid) { /* FIXME: get rid of drm_edid_raw() */ diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index ac90118b9e7a8..2bdbc1eb282bd 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -29,7 +29,6 @@ #include #include #include -#include #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) #include @@ -4723,18 +4722,6 @@ fail: return ret; } -static int do_get_act_status(struct drm_dp_aux *aux) -{ - int ret; - u8 status; - - ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); - if (ret < 0) - return ret; - - return status; -} - /** * drm_dp_check_act_status() - Polls for ACT handled status. * @mgr: manager to use @@ -4752,28 +4739,9 @@ int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr) * There doesn't seem to be any recommended retry count or timeout in * the MST specification. Since some hubs have been observed to take * over 1 second to update their payload allocations under certain - * conditions, we use a rather large timeout value. + * conditions, we use a rather large timeout value of 3 seconds. */ - const int timeout_ms = 3000; - int ret, status; - - ret = readx_poll_timeout(do_get_act_status, mgr->aux, status, - status & DP_PAYLOAD_ACT_HANDLED || status < 0, - 200, timeout_ms * USEC_PER_MSEC); - if (ret < 0 && status >= 0) { - drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n", - timeout_ms, status); - return -EINVAL; - } else if (status < 0) { - /* - * Failure here isn't unexpected - the hub may have - * just been unplugged - */ - drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status); - return status; - } - - return 0; + return drm_dp_dpcd_poll_act_handled(mgr->aux, 3000); } EXPORT_SYMBOL(drm_dp_check_act_status); diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h index 279624833ea92..38eea21d10828 100644 --- a/include/drm/display/drm_dp_helper.h +++ b/include/drm/display/drm_dp_helper.h @@ -567,6 +567,8 @@ int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux, enum drm_dp_phy dp_phy, u8 link_status[DP_LINK_STATUS_SIZE]); +int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms); + bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux, u8 real_edid_checksum);