From patchwork Thu Apr 14 12:19:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Sankeerth Billakanti (QUIC)" X-Patchwork-Id: 12813408 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D30C3C433FE for ; Thu, 14 Apr 2022 12:20:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243102AbiDNMWy (ORCPT ); Thu, 14 Apr 2022 08:22:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243155AbiDNMWl (ORCPT ); Thu, 14 Apr 2022 08:22:41 -0400 Received: from alexa-out-sd-01.qualcomm.com (alexa-out-sd-01.qualcomm.com [199.106.114.38]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 443C55677B; Thu, 14 Apr 2022 05:20:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1649938817; x=1681474817; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=ksne6/3PNnPyA13ih0N6IJsxup6aGcbTFWH9O3muco4=; b=AEdzqri/ZNUw2SU8kOY32+4ZCT+huGz2lETk62jPjekZlBl9ix4J2QmI 0IqIqG/16teXfICyrNvu+OvSrJY1eTh0XGsiBmbAB2BnEu92bq+8Rx2AN QKmaaHXN5AgrTlPSl3BBkmxTvnP0Mhsz5PKOhhln9mGNis39AjALdT01d Q=; Received: from unknown (HELO ironmsg03-sd.qualcomm.com) ([10.53.140.143]) by alexa-out-sd-01.qualcomm.com with ESMTP; 14 Apr 2022 05:20:17 -0700 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg03-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2022 05:20:15 -0700 Received: from nalasex01a.na.qualcomm.com (10.47.209.196) by nasanex01c.na.qualcomm.com (10.47.97.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Thu, 14 Apr 2022 05:20:15 -0700 Received: from sbillaka-linux.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Thu, 14 Apr 2022 05:20:08 -0700 From: Sankeerth Billakanti To: , , , , CC: Sankeerth Billakanti , , , , , , , , , , , , , , , Subject: [PATCH v7 3/4] drm/msm/dp: wait for hpd high before aux transaction Date: Thu, 14 Apr 2022 17:49:25 +0530 Message-ID: <1649938766-6768-4-git-send-email-quic_sbillaka@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1649938766-6768-1-git-send-email-quic_sbillaka@quicinc.com> References: <1649938766-6768-1-git-send-email-quic_sbillaka@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org The source device should ensure the sink is ready before proceeding to read the sink capability or perform any aux transactions. The sink will indicate its readiness by asserting the HPD line. The controller driver needs to wait for the hpd line to be asserted by the sink before it performs any aux transactions. The eDP sink is assumed to be always connected. It needs power from the source and its HPD line will be asserted only after the panel is powered on. The panel power will be enabled from the panel-edp driver and only after that, the hpd line will be asserted. Whereas for DP, the sink can be hotplugged and unplugged anytime. The hpd line gets asserted to indicate the sink is connected and ready. Hence there is no need to wait for the hpd line to be asserted for a DP sink. Signed-off-by: Sankeerth Billakanti Reviewed-by: Douglas Anderson --- Changes in v7: - add a comment to say why the wait si done for eDP - correct the commit text Changes in v6: - Wait for hpd high only for eDP - Split into smaller patches drivers/gpu/drm/msm/dp/dp_aux.c | 21 ++++++++++++++++++++- drivers/gpu/drm/msm/dp/dp_aux.h | 3 ++- drivers/gpu/drm/msm/dp/dp_catalog.c | 13 +++++++++++++ drivers/gpu/drm/msm/dp/dp_catalog.h | 1 + drivers/gpu/drm/msm/dp/dp_display.c | 2 +- 5 files changed, 37 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c index 6d36f63..cf0739f 100644 --- a/drivers/gpu/drm/msm/dp/dp_aux.c +++ b/drivers/gpu/drm/msm/dp/dp_aux.c @@ -36,6 +36,7 @@ struct dp_aux_private { bool initted; u32 offset; u32 segment; + bool is_edp; struct drm_dp_aux dp_aux; }; @@ -337,6 +338,22 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux, goto exit; } + /* + * For eDP it's important to give a reasonably long wait here for HPD + * to be asserted. This is because the panel driver may have _just_ + * turned on the panel and then tried to do an AUX transfer. The panel + * driver has no way of knowing when the panel is ready, so it's up + * to us to wait. For DP we never get into this situation so let's + * avoid ever doing the extra long wait for DP. + */ + if (aux->is_edp) { + ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog); + if (ret) { + DRM_DEBUG_DP("Panel not ready for aux transactions\n"); + goto exit; + } + } + dp_aux_update_offset_and_segment(aux, msg); dp_aux_transfer_helper(aux, msg, true); @@ -491,7 +508,8 @@ void dp_aux_unregister(struct drm_dp_aux *dp_aux) drm_dp_aux_unregister(dp_aux); } -struct drm_dp_aux *dp_aux_get(struct device *dev, struct dp_catalog *catalog) +struct drm_dp_aux *dp_aux_get(struct device *dev, struct dp_catalog *catalog, + bool is_edp) { struct dp_aux_private *aux; @@ -506,6 +524,7 @@ struct drm_dp_aux *dp_aux_get(struct device *dev, struct dp_catalog *catalog) init_completion(&aux->comp); aux->cmd_busy = false; + aux->is_edp = is_edp; mutex_init(&aux->mutex); aux->dev = dev; diff --git a/drivers/gpu/drm/msm/dp/dp_aux.h b/drivers/gpu/drm/msm/dp/dp_aux.h index 82afc8d..c99aeec 100644 --- a/drivers/gpu/drm/msm/dp/dp_aux.h +++ b/drivers/gpu/drm/msm/dp/dp_aux.h @@ -16,7 +16,8 @@ void dp_aux_init(struct drm_dp_aux *dp_aux); void dp_aux_deinit(struct drm_dp_aux *dp_aux); void dp_aux_reconfig(struct drm_dp_aux *dp_aux); -struct drm_dp_aux *dp_aux_get(struct device *dev, struct dp_catalog *catalog); +struct drm_dp_aux *dp_aux_get(struct device *dev, struct dp_catalog *catalog, + bool is_edp); void dp_aux_put(struct drm_dp_aux *aux); #endif /*__DP_AUX_H_*/ diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c index 07f2389..4282a98 100644 --- a/drivers/gpu/drm/msm/dp/dp_catalog.c +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c @@ -242,6 +242,19 @@ void dp_catalog_aux_update_cfg(struct dp_catalog *dp_catalog) phy_calibrate(phy); } +int dp_catalog_aux_wait_for_hpd_connect_state(struct dp_catalog *dp_catalog) +{ + u32 state; + struct dp_catalog_private *catalog = container_of(dp_catalog, + struct dp_catalog_private, dp_catalog); + + /* poll for hpd connected status every 2ms and timeout after 500ms */ + return readl_poll_timeout(catalog->io->dp_controller.aux.base + + REG_DP_DP_HPD_INT_STATUS, + state, state & DP_DP_HPD_STATE_STATUS_CONNECTED, + 2000, 500000); +} + static void dump_regs(void __iomem *base, int len) { int i; diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.h b/drivers/gpu/drm/msm/dp/dp_catalog.h index 7dea101..45140a3 100644 --- a/drivers/gpu/drm/msm/dp/dp_catalog.h +++ b/drivers/gpu/drm/msm/dp/dp_catalog.h @@ -84,6 +84,7 @@ int dp_catalog_aux_clear_hw_interrupts(struct dp_catalog *dp_catalog); void dp_catalog_aux_reset(struct dp_catalog *dp_catalog); void dp_catalog_aux_enable(struct dp_catalog *dp_catalog, bool enable); void dp_catalog_aux_update_cfg(struct dp_catalog *dp_catalog); +int dp_catalog_aux_wait_for_hpd_connect_state(struct dp_catalog *dp_catalog); u32 dp_catalog_aux_get_irq(struct dp_catalog *dp_catalog); /* DP Controller APIs */ diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index 1339c45..c7277f0 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -805,7 +805,7 @@ static int dp_init_sub_modules(struct dp_display_private *dp) goto error; } - dp->aux = dp_aux_get(dev, dp->catalog); + dp->aux = dp_aux_get(dev, dp->catalog, dp->dp_display.is_edp); if (IS_ERR(dp->aux)) { rc = PTR_ERR(dp->aux); DRM_ERROR("failed to initialize aux, rc = %d\n", rc);