net: wwan: t7xx: Ensure init is completed before system sleep

[ 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@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/wwan/t7xx/t7xx_pci.c b/drivers/net/wwan/t7xx/t7xx_pci.c
index 226fc17..91256e0 100644 (file)
--- 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 50b3705..5dffe24 100644 (file)
--- 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;