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Commit 5d3e24ee authored by Hemant Kumar's avatar Hemant Kumar Committed by Gerrit - the friendly Code Review server
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pci: msm: Use endpoint list to track suspend and resume 



Decouple endpoint event registration from link suspend.
Instead of relying on pending_ep_reg and num_active_ep
create an enumerated endpoint list at the time of endpoint
enumeration and move it to suspended endpoint list up
on link suspend. If enumerated endpoint list becomes
empty allow link suspend. Move endpoint back to enumerated
list upon resume. This also removes a race where all
endpoints have not completed their enumeration and one of
the endpoints request to suspend the link.

Change-Id: I22ac6e52a4c93d294d2a365da63cc7292e5e36ce
Signed-off-by: default avatarHemant Kumar <hemantk@codeaurora.org>
parent 3d8ab590

drivers/pci/controller/pci-msm.c

+97 −8
Original line number Diff line number Diff line
@@ -631,6 +631,7 @@ struct msm_pcie_sid_info_t { 


/* PCIe device info structure */

struct msm_pcie_device_info {

	struct list_head pcidev_node;

	u32 bdf;

	struct pci_dev *dev;

	short short_bdf;
@@ -847,6 +848,8 @@ struct msm_pcie_dev_t { 
	u32 num_active_ep;

	u32 num_ep;

	bool pending_ep_reg;

	struct list_head enum_ep_list;

	struct list_head susp_ep_list;

	u32 num_parf_testbus_sel;

	u32 phy_len;

	struct msm_pcie_phy_info_t *phy_sequence;
@@ -4790,6 +4793,7 @@ static void msm_pcie_disable(struct msm_pcie_dev_t *dev) 
static int msm_pcie_config_device_table(struct pci_dev *pcidev, void *pdev)

{

	struct msm_pcie_dev_t *pcie_dev = (struct msm_pcie_dev_t *) pdev;

	struct msm_pcie_device_info *dev_info;

	int ret = 0;

	u32 rc_idx = pcie_dev->rc_idx;

	u32 i;
@@ -4799,6 +4803,15 @@ static int msm_pcie_config_device_table(struct pci_dev *pcidev, void *pdev) 
		"PCI device found: vendor-id:0x%x device-id:0x%x\n",

		pcidev->vendor, pcidev->device);



	if (pci_pcie_type(pcidev) == PCI_EXP_TYPE_ENDPOINT) {

		dev_info = kzalloc(sizeof(*dev_info), GFP_KERNEL);

		if (!dev_info)

			return -ENOMEM;



		dev_info->dev = pcidev;

		list_add_tail(&dev_info->pcidev_node, &pcie_dev->enum_ep_list);

	}



	if (!pcidev->bus->number)

		return ret;
@@ -6476,6 +6489,7 @@ static int msm_pcie_remove(struct platform_device *pdev) 
{

	int ret = 0;

	int rc_idx;

	struct msm_pcie_device_info *dev_info;



	mutex_lock(&pcie_drv.drv_lock);
@@ -6495,6 +6509,18 @@ static int msm_pcie_remove(struct platform_device *pdev) 
	msm_pcie_gpio_deinit(&msm_pcie_dev[rc_idx]);

	msm_pcie_release_resources(&msm_pcie_dev[rc_idx]);



	list_for_each_entry(dev_info, &msm_pcie_dev[rc_idx].enum_ep_list,

			    pcidev_node) {

		list_del(&dev_info->pcidev_node);

		kfree(dev_info);

	}



	list_for_each_entry(dev_info, &msm_pcie_dev[rc_idx].susp_ep_list,

			    pcidev_node) {

		list_del(&dev_info->pcidev_node);

		kfree(dev_info);

	}



out:

	mutex_unlock(&pcie_drv.drv_lock);
@@ -7258,6 +7284,8 @@ static int __init pcie_init(void) 
				msm_pcie_drv_disable_pc);

		INIT_WORK(&msm_pcie_dev[i].drv_enable_pc_work,

				msm_pcie_drv_enable_pc);

		INIT_LIST_HEAD(&msm_pcie_dev[i].enum_ep_list);

		INIT_LIST_HEAD(&msm_pcie_dev[i].susp_ep_list);

	}



	if (i2c_add_driver(&pcie_i2c_ctrl_driver))
@@ -7879,6 +7907,8 @@ int msm_pcie_pm_control(enum msm_pcie_pm_opt pm_opt, u32 busnr, void *user, 
	struct pci_dev *dev;

	unsigned long flags;

	struct msm_pcie_dev_t *pcie_dev;

	struct msm_pcie_device_info *dev_info_itr, *dev_info = NULL;

	struct pci_dev *pcidev;



	if (!user) {

		pr_err("PCIe: endpoint device is NULL\n");
@@ -7902,6 +7932,8 @@ int msm_pcie_pm_control(enum msm_pcie_pm_opt pm_opt, u32 busnr, void *user, 


	dev = pcie_dev->dev;



	pcidev = (struct pci_dev *)user;



	if (!pcie_dev->drv_ready) {

		PCIE_ERR(pcie_dev,

			 "RC%d has not been successfully probed yet\n",
@@ -7936,18 +7968,37 @@ int msm_pcie_pm_control(enum msm_pcie_pm_opt pm_opt, u32 busnr, void *user, 
			break;

		}



		if (pcie_dev->pending_ep_reg) {

			PCIE_DBG(pcie_dev,

				 "PCIe: RC%d: request to suspend the link is rejected\n",

				 pcie_dev->rc_idx);

		mutex_lock(&pcie_dev->enumerate_lock);



		/*

		 * Remove current user requesting for suspend from ep list and

		 * add it to suspend ep list. Reject susp if list is still not

		 * empty.

		 */

		list_for_each_entry(dev_info_itr, &pcie_dev->enum_ep_list,

				    pcidev_node) {

			if (dev_info_itr->dev == pcidev) {

				list_del(&dev_info_itr->pcidev_node);

				dev_info = dev_info_itr;

				list_add_tail(&dev_info->pcidev_node,

					      &pcie_dev->susp_ep_list);

				break;

			}

		}



		if (pcie_dev->num_active_ep) {

		if (!dev_info)

			PCIE_DBG(pcie_dev,

				 "RC%d: an EP requested to suspend the link, but other EPs are still active: %d\n",

				 pcie_dev->rc_idx, pcie_dev->num_active_ep);

			return ret;

				 "PCIe: RC%d: ep BDF 0x%04x not in enum list\n",

				 pcie_dev->rc_idx, PCI_DEVID(

							pcidev->bus->number,

							pcidev->devfn));



		if (!list_empty(&pcie_dev->enum_ep_list)) {

			PCIE_DBG(pcie_dev,

				 "PCIe: RC%d: request to suspend the link is rejected\n",

				 pcie_dev->rc_idx);

			mutex_unlock(&pcie_dev->enumerate_lock);

			break;

		}



		pcie_dev->user_suspend = true;
@@ -7960,9 +8011,17 @@ int msm_pcie_pm_control(enum msm_pcie_pm_opt pm_opt, u32 busnr, void *user, 
				 "PCIe: RC%d: user failed to suspend the link.\n",

				 pcie_dev->rc_idx);

			pcie_dev->user_suspend = false;



			if (dev_info) {

				list_del(&dev_info->pcidev_node);

				list_add_tail(&dev_info->pcidev_node,

					      &pcie_dev->enum_ep_list);

			}

		}



		mutex_unlock(&pcie_dev->recovery_lock);



		mutex_unlock(&pcie_dev->enumerate_lock);

		break;

	case MSM_PCIE_RESUME:

		PCIE_DBG(pcie_dev,
@@ -7975,6 +8034,28 @@ int msm_pcie_pm_control(enum msm_pcie_pm_opt pm_opt, u32 busnr, void *user, 
			break;

		}



		/* when link was suspended and link resume is requested */

		mutex_lock(&pcie_dev->enumerate_lock);

		list_for_each_entry(dev_info_itr, &pcie_dev->susp_ep_list,

				    pcidev_node) {

			if (dev_info_itr->dev == user) {

				list_del(&dev_info_itr->pcidev_node);

				dev_info = dev_info_itr;

				list_add_tail(&dev_info->pcidev_node,

					      &pcie_dev->enum_ep_list);

				break;

			}

		}



		if (!dev_info) {

			PCIE_DBG(pcie_dev,

				 "PCIe: RC%d: ep BDF 0x%04x not in susp list\n",

				 pcie_dev->rc_idx, PCI_DEVID(

							pcidev->bus->number,

							pcidev->devfn));

		}

		mutex_unlock(&pcie_dev->enumerate_lock);



		if (pcie_dev->power_on) {

			PCIE_ERR(pcie_dev,

				 "PCIe: RC%d: requested to resume when link is already powered on. Number of active EP(s): %d\n",
@@ -7988,6 +8069,14 @@ int msm_pcie_pm_control(enum msm_pcie_pm_opt pm_opt, u32 busnr, void *user, 
			PCIE_ERR(pcie_dev,

				 "PCIe: RC%d: user failed to resume the link.\n",

				 pcie_dev->rc_idx);



			mutex_lock(&pcie_dev->enumerate_lock);

			if (dev_info) {

				list_del(&dev_info->pcidev_node);

				list_add_tail(&dev_info->pcidev_node,

					      &pcie_dev->susp_ep_list);

			}

			mutex_unlock(&pcie_dev->enumerate_lock);

		} else {

			PCIE_DBG(pcie_dev,

				 "PCIe: RC%d: user succeeded to resume the link.\n",