linux-kernel - [PATCH AUTOSEL 6.1 45/57] net: wwan: t7xx: Ensure init is completed before system sleep

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Message-Id: <20230525183607.1793983-45-sashal@kernel.org>
Date:   Thu, 25 May 2023 14:35:55 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Kai-Heng Feng <kai.heng.feng@...onical.com>,
        "David S . Miller" <davem@...emloft.net>,
        Sasha Levin <sashal@...nel.org>,
        chandrashekar.devegowda@...el.com, linuxwwan@...el.com,
        loic.poulain@...aro.org, ryazanov.s.a@...il.com,
        edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com,
        netdev@...r.kernel.org
Subject: [PATCH AUTOSEL 6.1 45/57] net: wwan: t7xx: Ensure init is completed before system sleep

From: Kai-Heng Feng <kai.heng.feng@...onical.com>

[ Upstream commit ab87603b251134441a67385ecc9d3371be17b7a7 ]

When the system attempts to sleep while mtk_t7xx is not ready, the driver
cannot put the device to sleep:
[   12.472918] mtk_t7xx 0000:57:00.0: [PM] Exiting suspend, modem in invalid state
[   12.472936] mtk_t7xx 0000:57:00.0: PM: pci_pm_suspend(): t7xx_pci_pm_suspend+0x0/0x20 [mtk_t7xx] returns -14
[   12.473678] mtk_t7xx 0000:57:00.0: PM: dpm_run_callback(): pci_pm_suspend+0x0/0x1b0 returns -14
[   12.473711] mtk_t7xx 0000:57:00.0: PM: failed to suspend async: error -14
[   12.764776] PM: Some devices failed to suspend, or early wake event detected

Mediatek confirmed the device can take a rather long time to complete
its initialization, so wait for up to 20 seconds until init is done.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@...onical.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/wwan/t7xx/t7xx_pci.c | 18 ++++++++++++++++++
 drivers/net/wwan/t7xx/t7xx_pci.h |  1 +
 2 files changed, 19 insertions(+)

diff --git a/drivers/net/wwan/t7xx/t7xx_pci.c b/drivers/net/wwan/t7xx/t7xx_pci.c
index 226fc1703e90f..91256e005b846 100644
--- a/drivers/net/wwan/t7xx/t7xx_pci.c
+++ b/drivers/net/wwan/t7xx/t7xx_pci.c
@@ -45,6 +45,7 @@
 #define T7XX_PCI_IREG_BASE		0
 #define T7XX_PCI_EREG_BASE		2
 
+#define T7XX_INIT_TIMEOUT		20
 #define PM_SLEEP_DIS_TIMEOUT_MS		20
 #define PM_ACK_TIMEOUT_MS		1500
 #define PM_AUTOSUSPEND_MS		20000
@@ -96,6 +97,7 @@ static int t7xx_pci_pm_init(struct t7xx_pci_dev *t7xx_dev)
 	spin_lock_init(&t7xx_dev->md_pm_lock);
 	init_completion(&t7xx_dev->sleep_lock_acquire);
 	init_completion(&t7xx_dev->pm_sr_ack);
+	init_completion(&t7xx_dev->init_done);
 	atomic_set(&t7xx_dev->md_pm_state, MTK_PM_INIT);
 
 	device_init_wakeup(&pdev->dev, true);
@@ -124,6 +126,7 @@ void t7xx_pci_pm_init_late(struct t7xx_pci_dev *t7xx_dev)
 	pm_runtime_mark_last_busy(&t7xx_dev->pdev->dev);
 	pm_runtime_allow(&t7xx_dev->pdev->dev);
 	pm_runtime_put_noidle(&t7xx_dev->pdev->dev);
+	complete_all(&t7xx_dev->init_done);
 }
 
 static int t7xx_pci_pm_reinit(struct t7xx_pci_dev *t7xx_dev)
@@ -529,6 +532,20 @@ static void t7xx_pci_shutdown(struct pci_dev *pdev)
 	__t7xx_pci_pm_suspend(pdev);
 }
 
+static int t7xx_pci_pm_prepare(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct t7xx_pci_dev *t7xx_dev;
+
+	t7xx_dev = pci_get_drvdata(pdev);
+	if (!wait_for_completion_timeout(&t7xx_dev->init_done, T7XX_INIT_TIMEOUT * HZ)) {
+		dev_warn(dev, "Not ready for system sleep.\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
 static int t7xx_pci_pm_suspend(struct device *dev)
 {
 	return __t7xx_pci_pm_suspend(to_pci_dev(dev));
@@ -555,6 +572,7 @@ static int t7xx_pci_pm_runtime_resume(struct device *dev)
 }
 
 static const struct dev_pm_ops t7xx_pci_pm_ops = {
+	.prepare = t7xx_pci_pm_prepare,
 	.suspend = t7xx_pci_pm_suspend,
 	.resume = t7xx_pci_pm_resume,
 	.resume_noirq = t7xx_pci_pm_resume_noirq,
diff --git a/drivers/net/wwan/t7xx/t7xx_pci.h b/drivers/net/wwan/t7xx/t7xx_pci.h
index 50b37056ce5a4..5dffe24ef37b4 100644
--- a/drivers/net/wwan/t7xx/t7xx_pci.h
+++ b/drivers/net/wwan/t7xx/t7xx_pci.h
@@ -69,6 +69,7 @@ struct t7xx_pci_dev {
 	struct t7xx_modem	*md;
 	struct t7xx_ccmni_ctrl	*ccmni_ctlb;
 	bool			rgu_pci_irq_en;
+	struct completion	init_done;
 
 	/* Low Power Items */
 	struct list_head	md_pm_entities;
-- 
2.39.2