[PATCH 10/11] net: wwan: t9xx: Add power management support
Jagielski, Jedrzej
jedrzej.jagielski at intel.com
Mon Jun 1 05:26:37 PDT 2026
From: Jack Wu via B4 Relay <devnull+jackbb_wu.compal.com at kernel.org>
Sent: Friday, May 29, 2026 12:32 PM
>From: Jack Wu <jackbb_wu at compal.com>
>
>Add s2idle (S0ix) power management support for the t9xx WWAN driver.
>
>In s2idle the modem remains powered. The driver must quiesce host-side
>DMA engines and service threads before the platform enters low-power
>state, then restore them on resume.
>
>- Suspend: park TRB service threads, stop CLDMA TX/RX queues,
> disable DPMAIF data path, mask MHCCIF and MSIX interrupts,
> save PCIe state
>- Resume: restore PCIe state, re-initialize ATR, unmask MHCCIF,
> resume CLDMA queues, re-enable DPMAIF data path, unpark TRB
> service threads
>
>Signed-off-by: Jack Wu <jackbb_wu at compal.com>
>---
> drivers/net/wwan/t9xx/pcie/mtk_cldma.c | 94 +++++++++++++++++++++++++++++++++
> drivers/net/wwan/t9xx/pcie/mtk_cldma.h | 3 ++
> drivers/net/wwan/t9xx/pcie/mtk_dpmaif.c | 35 +++++++++++-
> drivers/net/wwan/t9xx/pcie/mtk_dpmaif.h | 2 +
> drivers/net/wwan/t9xx/pcie/mtk_pci.c | 85 ++++++++++++++++++++++++++++-
> 5 files changed, 216 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/net/wwan/t9xx/pcie/mtk_cldma.c b/drivers/net/wwan/t9xx/pcie/mtk_cldma.c
>index aacb4177d914..a5227eb546f4 100644
>--- a/drivers/net/wwan/t9xx/pcie/mtk_cldma.c
>+++ b/drivers/net/wwan/t9xx/pcie/mtk_cldma.c
>@@ -1113,6 +1113,100 @@ int mtk_cldma_exit(struct mtk_ctrl_trans *trans)
> return 0;
> }
>
>+void mtk_cldma_pm_suspend(struct mtk_md_dev *mdev)
>+{
>+ struct mtk_ctrl_trans *trans = ((struct mtk_ctrl_blk *)mdev->ctrl_blk)->ctrl_hw_priv;
>+ struct cldma_dev *cd = trans->dev;
>+ struct cldma_drv_info *drv_info;
>+ struct cldma_drv_ops *drv_ops;
>+ struct rxq *rxq;
>+ struct txq *txq;
>+ int i, q;
>+
>+ for (i = 0; i < NR_CLDMA; i++) {
>+ drv_info = cd->cldma_drv_info[i];
>+ if (!drv_info)
>+ continue;
>+
>+ drv_ops = drv_info->drv_ops;
>+
>+ /* Stop TX queues and flush pending tx_done_work (suspend phase) */
>+ drv_ops->cldma_stop_queue(drv_info, DIR_TX, ALLQ);
>+ for (q = 0; q < HW_QUEUE_NUM; q++) {
>+ txq = drv_info->txq[q];
>+ if (txq)
>+ flush_work(&txq->tx_done_work);
>+ }
>+
>+ for (q = 0; q < HW_QUEUE_NUM; q++) {
>+ rxq = drv_info->rxq[q];
>+ if (!rxq)
>+ continue;
>+ atomic_set(&rxq->need_exit, 1);
>+ drv_ops->cldma_stop_queue(drv_info, DIR_RX, q);
>+ flush_work(&rxq->rx_done_work);
>+ }
>+ mtk_pci_mask_irq(mdev, drv_info->pci_ext_irq_id);
>+ }
>+}
>+
>+void mtk_cldma_pm_resume_early(struct mtk_md_dev *mdev)
>+{
>+ struct mtk_ctrl_trans *trans = ((struct mtk_ctrl_blk *)mdev->ctrl_blk)->ctrl_hw_priv;
>+ struct cldma_dev *cd = trans->dev;
>+ struct cldma_drv_info *drv_info;
>+ struct cldma_drv_ops *drv_ops;
>+ struct rxq *rxq;
>+ int i, q;
>+
>+ for (i = 0; i < NR_CLDMA; i++) {
>+ drv_info = cd->cldma_drv_info[i];
>+ if (!drv_info)
>+ continue;
>+
>+ drv_ops = drv_info->drv_ops;
>+
>+ /* Resume RX queues from current HW ring position (no addr reset) */
>+ for (q = 0; q < HW_QUEUE_NUM; q++) {
>+ rxq = drv_info->rxq[q];
>+ if (!rxq)
>+ continue;
>+ atomic_set(&rxq->need_exit, 0);
>+ drv_ops->cldma_resume_queue(drv_info, DIR_RX, q);
>+ }
>+
>+ /* Unmask CLDMA L1 interrupt */
>+ mtk_pci_unmask_irq(mdev, drv_info->pci_ext_irq_id);
>+ }
>+}
>+
>+void mtk_cldma_pm_resume(struct mtk_md_dev *mdev)
>+{
>+ struct mtk_ctrl_trans *trans = ((struct mtk_ctrl_blk *)mdev->ctrl_blk)->ctrl_hw_priv;
>+ struct cldma_dev *cd = trans->dev;
>+ struct cldma_drv_info *drv_info;
>+ struct cldma_drv_ops *drv_ops;
>+ struct txq *txq;
>+ int i, q;
>+
>+ for (i = 0; i < NR_CLDMA; i++) {
>+ drv_info = cd->cldma_drv_info[i];
>+ if (!drv_info)
>+ continue;
>+
>+ drv_ops = drv_info->drv_ops;
>+
>+ /* Restart TX queues that have pending descriptors */
>+ for (q = 0; q < HW_QUEUE_NUM; q++) {
>+ txq = drv_info->txq[q];
>+ if (!txq)
>+ continue;
>+ if (atomic_read(&txq->req_budget) < txq->nr_gpds)
>+ mtk_cldma_start_xfer(drv_info, q);
>+ }
>+ }
>+}
>+
> static int mtk_cldma_open(struct cldma_dev *cd, struct sk_buff *skb)
> {
> struct trb_open_priv *trb_open_priv = (struct trb_open_priv *)skb->data;
>diff --git a/drivers/net/wwan/t9xx/pcie/mtk_cldma.h b/drivers/net/wwan/t9xx/pcie/mtk_cldma.h
>index 04f83ff0e37d..fd39985f75e7 100644
>--- a/drivers/net/wwan/t9xx/pcie/mtk_cldma.h
>+++ b/drivers/net/wwan/t9xx/pcie/mtk_cldma.h
>@@ -163,6 +163,9 @@ int mtk_cldma_get_tx_budget(void *dev, enum mtk_hif_id hif_id, u32 qno);
> int mtk_cldma_trb_process(void *dev, struct sk_buff *skb);
> void mtk_cldma_fsm_state_listener(struct mtk_fsm_param *param, struct mtk_ctrl_trans *trans);
> int mtk_cldma_check_ch_cfg(void *dev, struct queue_info *que);
>+void mtk_cldma_pm_suspend(struct mtk_md_dev *mdev);
>+void mtk_cldma_pm_resume_early(struct mtk_md_dev *mdev);
>+void mtk_cldma_pm_resume(struct mtk_md_dev *mdev);
>
> #define drv_ops_name(NAME) cldma_drv_ops_##NAME
> #define cldma_regs_name(NAME) mtk_cldma_regs_##NAME
>diff --git a/drivers/net/wwan/t9xx/pcie/mtk_dpmaif.c b/drivers/net/wwan/t9xx/pcie/mtk_dpmaif.c
>index 43803587bfc3..63273a85e532 100644
>--- a/drivers/net/wwan/t9xx/pcie/mtk_dpmaif.c
>+++ b/drivers/net/wwan/t9xx/pcie/mtk_dpmaif.c
>@@ -205,6 +205,7 @@ struct mtk_dpmaif_ctlb {
> struct dpmaif_irq_param *irq_params;
>
> bool dpmaif_sw_reset;
>+ bool trans_enabled;
> unsigned char rxq_cnt;
> unsigned char txq_cnt;
> };
>@@ -1687,10 +1688,16 @@ static void mtk_dpmaif_trans_disable(struct mtk_dpmaif_ctlb *dcb)
> static void mtk_dpmaif_trans_ctl(struct mtk_dpmaif_ctlb *dcb, bool enable)
> {
> if (enable) {
>- if (dcb->dpmaif_state == DPMAIF_STATE_PWRON)
>+ if (!dcb->trans_enabled &&
>+ dcb->dpmaif_state == DPMAIF_STATE_PWRON) {
>+ dcb->trans_enabled = true;
> mtk_dpmaif_trans_enable(dcb);
>+ }
> } else {
>- mtk_dpmaif_trans_disable(dcb);
>+ if (dcb->trans_enabled) {
should it be done unconditionally from DPMAIF_STATE_PWRON?
>+ dcb->trans_enabled = false;
>+ mtk_dpmaif_trans_disable(dcb);
>+ }
> }
> }
>
>@@ -2060,6 +2067,30 @@ static int mtk_dpmaif_stop(struct mtk_md_dev *mdev)
> return 0;
> }
>
>+void mtk_dpmaif_pm_suspend(struct mtk_md_dev *mdev)
>+{
>+ struct mtk_dpmaif_ctlb *dcb = ((struct mtk_data_blk *)(mdev->data_blk))->dcb;
>+
>+ if (!dcb)
>+ return;
>+
>+ mutex_lock(&dcb->trans_ctl_lock);
>+ mtk_dpmaif_trans_ctl(dcb, false);
>+ mutex_unlock(&dcb->trans_ctl_lock);
>+}
>+
>+void mtk_dpmaif_pm_resume(struct mtk_md_dev *mdev)
>+{
>+ struct mtk_dpmaif_ctlb *dcb = ((struct mtk_data_blk *)(mdev->data_blk))->dcb;
>+
>+ if (!dcb)
>+ return;
>+
>+ mutex_lock(&dcb->trans_ctl_lock);
>+ mtk_dpmaif_trans_ctl(dcb, true);
>+ mutex_unlock(&dcb->trans_ctl_lock);
>+}
>+
> static void mtk_dpmaif_clear(struct mtk_md_dev *mdev)
> {
> struct mtk_dpmaif_ctlb *dcb = ((struct mtk_data_blk *)(mdev->data_blk))->dcb;
>diff --git a/drivers/net/wwan/t9xx/pcie/mtk_dpmaif.h b/drivers/net/wwan/t9xx/pcie/mtk_dpmaif.h
>index e7e2f333141c..20fd53fd44b5 100644
>--- a/drivers/net/wwan/t9xx/pcie/mtk_dpmaif.h
>+++ b/drivers/net/wwan/t9xx/pcie/mtk_dpmaif.h
>@@ -10,5 +10,7 @@
>
> int mtk_pcie_data_init(struct mtk_md_dev *mdev);
> int mtk_pcie_data_exit(struct mtk_md_dev *mdev);
>+void mtk_dpmaif_pm_suspend(struct mtk_md_dev *mdev);
>+void mtk_dpmaif_pm_resume(struct mtk_md_dev *mdev);
>
> #endif /* __MTK_DPMAIF_H__ */
>diff --git a/drivers/net/wwan/t9xx/pcie/mtk_pci.c b/drivers/net/wwan/t9xx/pcie/mtk_pci.c
>index baac3692f1e3..f659c9a7aa96 100644
>--- a/drivers/net/wwan/t9xx/pcie/mtk_pci.c
>+++ b/drivers/net/wwan/t9xx/pcie/mtk_pci.c
>@@ -11,8 +11,10 @@
> #include <linux/device.h>
> #include <linux/dma-mapping.h>
> #include <linux/kernel.h>
>+#include <linux/kthread.h>
> #include <linux/module.h>
>
>+#include "mtk_cldma.h"
> #include "mtk_dev.h"
> #include "mtk_dpmaif.h"
> #include "mtk_trans_ctrl.h"
>@@ -199,7 +201,6 @@ int mtk_pci_register_irq(struct mtk_md_dev *mdev, int irq_id,
> }
> priv->irq_cb_list[irq_id] = irq_cb;
> priv->irq_cb_data[irq_id] = data;
>-
> return 0;
> }
>
>@@ -970,11 +971,93 @@ static const struct pci_error_handlers mtk_pci_err_handler = {
> .error_detected = mtk_pci_error_detected,
> };
>
>+static void mtk_pci_pm_trb_park(struct mtk_md_dev *mdev)
>+{
>+ struct mtk_ctrl_trans *trans = ((struct mtk_ctrl_blk *)mdev->ctrl_blk)->ctrl_hw_priv;
>+ int i;
>+
>+ for (i = 0; i < trans->trb_srv_num; i++)
>+ kthread_park(trans->trb_srv[i]->trb_thread);
>+}
>+
>+static void mtk_pci_pm_trb_unpark(struct mtk_md_dev *mdev)
>+{
>+ struct mtk_ctrl_trans *trans = ((struct mtk_ctrl_blk *)mdev->ctrl_blk)->ctrl_hw_priv;
>+ int i;
>+
>+ for (i = 0; i < trans->trb_srv_num; i++)
>+ kthread_unpark(trans->trb_srv[i]->trb_thread);
>+}
>+
>+static int __maybe_unused mtk_pci_pm_suspend(struct device *dev)
>+{
>+ struct pci_dev *pdev = to_pci_dev(dev);
>+ struct mtk_md_dev *mdev = pci_get_drvdata(pdev);
>+ struct mtk_pci_priv *priv = mdev->hw_priv;
RCT
>+
>+ mtk_pci_pm_trb_park(mdev);
>+
>+ mtk_cldma_pm_suspend(mdev);
>+
>+ mtk_dpmaif_pm_suspend(mdev);
>+
>+ /* Mask MHCCIF interrupt */
>+ mtk_pci_mask_irq(mdev, priv->mhccif_irq_id);
>+
>+ /* Mask all MSI-X interrupts at the device level */
>+ mtk_pci_mac_write32(priv, REG_IMASK_HOST_MSIX_CLR_GRP0_0, U32_MAX);
>+
>+ /* Save PCI configuration space */
>+ pci_save_state(pdev);
>+
>+ return 0;
>+}
>+
>+static int __maybe_unused mtk_pci_pm_resume(struct device *dev)
>+{
>+ struct pci_dev *pdev = to_pci_dev(dev);
>+ struct mtk_md_dev *mdev = pci_get_drvdata(pdev);
>+ struct mtk_pci_priv *priv = mdev->hw_priv;
>+ int ret;
>+
>+ /* Restore PCIe configuration space (including MSI-X enable bits) */
these comments are rather obvious
>+ pci_restore_state(pdev);
>+
>+ /* Re-enable bus mastering for DMA */
>+ pci_set_master(pdev);
>+
>+ /* Restore ATR (address translation registers in MMIO BAR space) */
>+ ret = priv->cfg->atr_init(mdev);
>+ if (ret) {
>+ dev_err(mdev->dev, "PM: failed to re-init ATR on resume\n");
>+ return ret;
>+ }
>+
>+ /* Unmask MHCCIF interrupt */
>+ mtk_pci_unmask_irq(mdev, priv->mhccif_irq_id);
>+
>+ mtk_cldma_pm_resume_early(mdev);
>+
>+ /* Restart CLDMA TX queues that have pending descriptors */
>+ mtk_cldma_pm_resume(mdev);
>+
>+ mtk_dpmaif_pm_resume(mdev);
>+
>+ mtk_pci_pm_trb_unpark(mdev);
>+
>+ return 0;
>+}
>+
>+static const struct dev_pm_ops mtk_pci_pm_ops = {
>+ SET_SYSTEM_SLEEP_PM_OPS(mtk_pci_pm_suspend, mtk_pci_pm_resume)
>+};
>+
> static struct pci_driver mtk_pci_drv = {
> .name = "mtk_pci_drv",
> .id_table = t9xx_pci_table,
> .probe = mtk_pci_probe,
> .remove = mtk_pci_remove,
>+ .driver.pm = &mtk_pci_pm_ops,
> .err_handler = &mtk_pci_err_handler
> };
>
>
>--
>2.34.1
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