From patchwork Fri Mar 15 23:09:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Anderson X-Patchwork-Id: 13594129 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 92CA7C54E68 for ; Fri, 15 Mar 2024 23:10:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=b7GJnGdnbPwgN3BabuhXnZXk/DGZqyXgOt8MtZrkxAU=; b=jyM+v2iPL5Mw6t jVuz7Jzp9SwKSaVnvcLxt0SBjG8/tLdGt3lDAPUJpw8gTxRon60EVdS2B28OI9r68SLCsuDbEYFA1 wasUPksCAfuIACsmMRvpX9Xd37YvJumXm6E5W7fXozxYeslY3i20x8gPbDcrUCj9Mj+WBZaGHvIPQ 3R/ijGYhNi2MsIoW0y9T2DNmmVexYSM4DKdhCoKlLQ9siPjr5g/f0stZ6q2LLs6vK4jiXtg2e8tvM G3Sb7pyPN3WBwGrVexEmrSUIzVHiTAnjKkGc51DspslOpVmjkD34IRLItY9eS1c9DtmB0bDJC3L4X 1gLZrRhIgZQd6dwSO+4Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rlGgN-00000001pEw-01fa; Fri, 15 Mar 2024 23:09:47 +0000 Received: from out-183.mta1.migadu.com ([2001:41d0:203:375::b7]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rlGg8-00000001p4p-0bHX for linux-arm-kernel@lists.infradead.org; Fri, 15 Mar 2024 23:09:37 +0000 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1710544169; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=x3+PPHKFdpXChJ2kv+csEq7dgWK3ohjxhbsPdG1wSL8=; b=sCTuaiSCAibV4U3YanvC1CP7RQ4P/1K1uVl4TF+QK3DoU//lK/I48pIMz7ptYb/yNP48IV 1EGWc9lPRUdMfu7SNC87Rl5ZkIedou7jEXCMxqE3IHEIhcF6SexqcRCgcOwl/I0QqPYYuF FnBDtEn2cPx1zIM/RQVpgv64myIUmRo= From: Sean Anderson To: Laurent Pinchart , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , dri-devel@lists.freedesktop.org Cc: David Airlie , linux-kernel@vger.kernel.org, Michal Simek , linux-arm-kernel@lists.infradead.org, Daniel Vetter , Sean Anderson Subject: [PATCH 3/6] drm: zynqmp_dp: Add locking Date: Fri, 15 Mar 2024 19:09:13 -0400 Message-Id: <20240315230916.1759060-4-sean.anderson@linux.dev> In-Reply-To: <20240315230916.1759060-1-sean.anderson@linux.dev> References: <20240315230916.1759060-1-sean.anderson@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240315_160932_348028_58357587 X-CRM114-Status: GOOD ( 14.92 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add some locking, since none is provided by the drm subsystem. This will prevent the IRQ/workers/bridge API calls from stepping on each other's toes. Signed-off-by: Sean Anderson --- drivers/gpu/drm/xlnx/zynqmp_dp.c | 59 +++++++++++++++++++++++--------- 1 file changed, 42 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c index 8635b5673386..d2dee58e7bf2 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c @@ -279,6 +279,7 @@ struct zynqmp_dp_config { * @dpsub: Display subsystem * @iomem: device I/O memory for register access * @reset: reset controller + * @lock: Mutex protecting this struct and register access (but not AUX) * @irq: irq * @bridge: DRM bridge for the DP encoder * @next_bridge: The downstream bridge @@ -299,6 +300,7 @@ struct zynqmp_dp { struct zynqmp_dpsub *dpsub; void __iomem *iomem; struct reset_control *reset; + struct mutex lock; int irq; struct drm_bridge bridge; @@ -308,7 +310,7 @@ struct zynqmp_dp { struct drm_dp_aux aux; struct phy *phy[ZYNQMP_DP_MAX_LANES]; u8 num_lanes; - struct delayed_work hpd_work; + struct delayed_work hpd_work, hpd_irq_work; enum drm_connector_status status; bool enabled; @@ -1371,8 +1373,10 @@ zynqmp_dp_bridge_mode_valid(struct drm_bridge *bridge, } /* Check with link rate and lane count */ + mutex_lock(&dp->lock); rate = zynqmp_dp_max_rate(dp->link_config.max_rate, dp->link_config.max_lanes, dp->config.bpp); + mutex_unlock(&dp->lock); if (mode->clock > rate) { dev_dbg(dp->dev, "filtered mode %s for high pixel rate\n", mode->name); @@ -1399,6 +1403,7 @@ static void zynqmp_dp_bridge_atomic_enable(struct drm_bridge *bridge, pm_runtime_get_sync(dp->dev); + mutex_lock(&dp->lock); zynqmp_dp_disp_enable(dp, old_bridge_state); /* @@ -1459,6 +1464,7 @@ static void zynqmp_dp_bridge_atomic_enable(struct drm_bridge *bridge, zynqmp_dp_write(dp, ZYNQMP_DP_SOFTWARE_RESET, ZYNQMP_DP_SOFTWARE_RESET_ALL); zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 1); + mutex_unlock(&dp->lock); } static void zynqmp_dp_bridge_atomic_disable(struct drm_bridge *bridge, @@ -1466,6 +1472,7 @@ static void zynqmp_dp_bridge_atomic_disable(struct drm_bridge *bridge, { struct zynqmp_dp *dp = bridge_to_dp(bridge); + mutex_lock(&dp->lock); dp->enabled = false; cancel_delayed_work(&dp->hpd_work); zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 0); @@ -1476,6 +1483,7 @@ static void zynqmp_dp_bridge_atomic_disable(struct drm_bridge *bridge, zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 0); zynqmp_dp_disp_disable(dp, old_bridge_state); + mutex_unlock(&dp->lock); pm_runtime_put_sync(dp->dev); } @@ -1518,6 +1526,8 @@ static enum drm_connector_status zynqmp_dp_bridge_detect(struct drm_bridge *brid u32 state, i; int ret; + mutex_lock(&dp->lock); + /* * This is from heuristic. It takes some delay (ex, 100 ~ 500 msec) to * get the HPD signal with some monitors. @@ -1545,11 +1555,13 @@ static enum drm_connector_status zynqmp_dp_bridge_detect(struct drm_bridge *brid dp->num_lanes); dp->status = connector_status_connected; + mutex_unlock(&dp->lock); return connector_status_connected; } disconnected: dp->status = connector_status_disconnected; + mutex_unlock(&dp->lock); return connector_status_disconnected; } @@ -1611,6 +1623,29 @@ static void zynqmp_dp_hpd_work_func(struct work_struct *work) drm_bridge_hpd_notify(&dp->bridge, status); } +static void zynqmp_dp_hpd_irq_work_func(struct work_struct *work) +{ + struct zynqmp_dp *dp = container_of(work, struct zynqmp_dp, + hpd_irq_work.work); + u8 status[DP_LINK_STATUS_SIZE + 2]; + int err; + + mutex_lock(&dp->lock); + err = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status, + DP_LINK_STATUS_SIZE + 2); + if (err < 0) { + dev_dbg_ratelimited(dp->dev, + "could not read sink status: %d\n", err); + } else { + if (status[4] & DP_LINK_STATUS_UPDATED || + !drm_dp_clock_recovery_ok(&status[2], dp->mode.lane_cnt) || + !drm_dp_channel_eq_ok(&status[2], dp->mode.lane_cnt)) { + zynqmp_dp_train_loop(dp); + } + } + mutex_unlock(&dp->lock); +} + static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data) { struct zynqmp_dp *dp = (struct zynqmp_dp *)data; @@ -1635,23 +1670,9 @@ static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data) if (status & ZYNQMP_DP_INT_HPD_EVENT) schedule_delayed_work(&dp->hpd_work, 0); - if (status & ZYNQMP_DP_INT_HPD_IRQ) { - int ret; - u8 status[DP_LINK_STATUS_SIZE + 2]; + if (status & ZYNQMP_DP_INT_HPD_IRQ) + schedule_delayed_work(&dp->hpd_irq_work, 0); - ret = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status, - DP_LINK_STATUS_SIZE + 2); - if (ret < 0) - goto handled; - - if (status[4] & DP_LINK_STATUS_UPDATED || - !drm_dp_clock_recovery_ok(&status[2], dp->mode.lane_cnt) || - !drm_dp_channel_eq_ok(&status[2], dp->mode.lane_cnt)) { - zynqmp_dp_train_loop(dp); - } - } - -handled: return IRQ_HANDLED; } @@ -1674,8 +1695,10 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub) dp->dev = &pdev->dev; dp->dpsub = dpsub; dp->status = connector_status_disconnected; + mutex_init(&dp->lock); INIT_DELAYED_WORK(&dp->hpd_work, zynqmp_dp_hpd_work_func); + INIT_DELAYED_WORK(&dp->hpd_irq_work, zynqmp_dp_hpd_irq_work_func); /* Acquire all resources (IOMEM, IRQ and PHYs). */ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dp"); @@ -1775,6 +1798,7 @@ void zynqmp_dp_remove(struct zynqmp_dpsub *dpsub) zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_ALL); disable_irq(dp->irq); + cancel_delayed_work_sync(&dp->hpd_irq_work); cancel_delayed_work_sync(&dp->hpd_work); zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0); @@ -1782,4 +1806,5 @@ void zynqmp_dp_remove(struct zynqmp_dpsub *dpsub) zynqmp_dp_phy_exit(dp); zynqmp_dp_reset(dp, true); + mutex_destroy(&dp->lock); }