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Commit 49564a80 authored by Luca Coelho's avatar Luca Coelho
Browse files

iwlwifi: pcie: remove non-responsive device 



If we fail to to grab NIC access because the device is not responding
(i.e. CSR_GP_CNTRL returns 0xFFFFFFFF), remove the device from the PCI
bus, to avoid any further damage, and to let the user space rescan.

In order to inform the userspace that a rescan is needed, we send a
kobject uevent with "INACCESSIBLE".

This functionality is disabled by default, but can be enabled via a
new module parameter called "remove_when_gone".  In the future we may
change this module parameter to include 3 modes instead: do nothing;
auto-rescan or; send uevent.

Signed-off-by: default avatarLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: default avatarRajat Jain <rajatja@google.com>
parent de460ddd

drivers/net/wireless/intel/iwlwifi/iwl-drv.c

+6 −0
Original line number Original line Diff line number Diff line
@@ -1850,3 +1850,9 @@ MODULE_PARM_DESC(d0i3_timeout, "Timeout to D0i3 entry when idle (ms)"); 




module_param_named(disable_11ac, iwlwifi_mod_params.disable_11ac, bool, 0444);

module_param_named(disable_11ac, iwlwifi_mod_params.disable_11ac, bool, 0444);

MODULE_PARM_DESC(disable_11ac, "Disable VHT capabilities (default: false)");

MODULE_PARM_DESC(disable_11ac, "Disable VHT capabilities (default: false)");



module_param_named(remove_when_gone,

		   iwlwifi_mod_params.remove_when_gone, bool,

		   0444);

MODULE_PARM_DESC(remove_when_gone,

		 "Remove dev from PCIe bus if it is deemed inaccessible (default: false)");

drivers/net/wireless/intel/iwlwifi/iwl-modparams.h

+2 −0
Original line number Original line Diff line number Diff line
@@ -122,6 +122,7 @@ enum iwl_uapsd_disable { 
 * @lar_disable: disable LAR (regulatory), default = 0

 * @lar_disable: disable LAR (regulatory), default = 0

 * @fw_monitor: allow to use firmware monitor

 * @fw_monitor: allow to use firmware monitor

 * @disable_11ac: disable VHT capabilities, default = false.

 * @disable_11ac: disable VHT capabilities, default = false.

 * @remove_when_gone: remove an inaccessible device from the PCIe bus.

 */

 */

struct iwl_mod_params {

struct iwl_mod_params {

	int swcrypto;

	int swcrypto;
@@ -143,6 +144,7 @@ struct iwl_mod_params { 
	bool lar_disable;

	bool lar_disable;

	bool fw_monitor;

	bool fw_monitor;

	bool disable_11ac;

	bool disable_11ac;

	bool remove_when_gone;

};

};





#endif /* #__iwl_modparams_h__ */
 
#endif /* #__iwl_modparams_h__ */

drivers/net/wireless/intel/iwlwifi/pcie/internal.h

+5 −0
Original line number Original line Diff line number Diff line
@@ -383,6 +383,8 @@ struct iwl_self_init_dram { 
 * @hw_init_mask: initial unmasked hw causes

 * @hw_init_mask: initial unmasked hw causes

 * @fh_mask: current unmasked fh causes

 * @fh_mask: current unmasked fh causes

 * @hw_mask: current unmasked hw causes

 * @hw_mask: current unmasked hw causes

 * @in_rescan: true if we have triggered a device rescan

 * @scheduled_for_removal: true if we have scheduled a device removal

 */

 */

struct iwl_trans_pcie {

struct iwl_trans_pcie {

	struct iwl_rxq *rxq;

	struct iwl_rxq *rxq;
@@ -464,6 +466,9 @@ struct iwl_trans_pcie { 
	u32 fh_mask;

	u32 fh_mask;

	u32 hw_mask;

	u32 hw_mask;

	cpumask_t affinity_mask[IWL_MAX_RX_HW_QUEUES];

	cpumask_t affinity_mask[IWL_MAX_RX_HW_QUEUES];

	u16 tx_cmd_queue_size;

	bool in_rescan;

	bool scheduled_for_removal;

};

};





static inline struct iwl_trans_pcie *

static inline struct iwl_trans_pcie *

drivers/net/wireless/intel/iwlwifi/pcie/trans.c

+71 −3
Original line number Original line Diff line number Diff line
@@ -75,6 +75,7 @@ 
#include <linux/gfp.h>

#include <linux/gfp.h>

#include <linux/vmalloc.h>

#include <linux/vmalloc.h>

#include <linux/pm_runtime.h>

#include <linux/pm_runtime.h>

#include <linux/module.h>





#include "iwl-drv.h"

#include "iwl-drv.h"

#include "iwl-trans.h"

#include "iwl-trans.h"
@@ -1935,6 +1936,29 @@ static void iwl_trans_pcie_set_pmi(struct iwl_trans *trans, bool state) 
		clear_bit(STATUS_TPOWER_PMI, &trans->status);

		clear_bit(STATUS_TPOWER_PMI, &trans->status);

}

}





struct iwl_trans_pcie_removal {

	struct pci_dev *pdev;

	struct work_struct work;

};



static void iwl_trans_pcie_removal_wk(struct work_struct *wk)

{

	struct iwl_trans_pcie_removal *removal =

		container_of(wk, struct iwl_trans_pcie_removal, work);

	struct pci_dev *pdev = removal->pdev;

	char *prop[] = {"EVENT=INACCESSIBLE", NULL};



	dev_err(&pdev->dev, "Device gone - attempting removal\n");

	kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, prop);

	pci_lock_rescan_remove();

	pci_dev_put(pdev);

	pci_stop_and_remove_bus_device(pdev);

	pci_unlock_rescan_remove();



	kfree(removal);

	module_put(THIS_MODULE);

}



static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans,

static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans,

					   unsigned long *flags)

					   unsigned long *flags)

{

{
@@ -1977,11 +2001,55 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans, 
			   (BIT(trans->cfg->csr->flag_mac_clock_ready) |

			   (BIT(trans->cfg->csr->flag_mac_clock_ready) |

			    CSR_GP_CNTRL_REG_FLAG_GOING_TO_SLEEP), 15000);

			    CSR_GP_CNTRL_REG_FLAG_GOING_TO_SLEEP), 15000);

	if (unlikely(ret < 0)) {

	if (unlikely(ret < 0)) {

		iwl_trans_pcie_dump_regs(trans);

		u32 cntrl = iwl_read32(trans, CSR_GP_CNTRL);

		iwl_write32(trans, CSR_RESET, CSR_RESET_REG_FLAG_FORCE_NMI);



		WARN_ONCE(1,

		WARN_ONCE(1,

			  "Timeout waiting for hardware access (CSR_GP_CNTRL 0x%08x)\n",

			  "Timeout waiting for hardware access (CSR_GP_CNTRL 0x%08x)\n",

			  iwl_read32(trans, CSR_GP_CNTRL));

			  cntrl);



		iwl_trans_pcie_dump_regs(trans);



		if (iwlwifi_mod_params.remove_when_gone && cntrl == ~0U) {

			struct iwl_trans_pcie_removal *removal;



			if (trans_pcie->scheduled_for_removal)

				goto err;



			IWL_ERR(trans, "Device gone - scheduling removal!\n");



			/*

			 * get a module reference to avoid doing this

			 * while unloading anyway and to avoid

			 * scheduling a work with code that's being

			 * removed.

			 */

			if (!try_module_get(THIS_MODULE)) {

				IWL_ERR(trans,

					"Module is being unloaded - abort\n");

				goto err;

			}



			removal = kzalloc(sizeof(*removal), GFP_ATOMIC);

			if (!removal) {

				module_put(THIS_MODULE);

				goto err;

			}

			/*

			 * we don't need to clear this flag, because

			 * the trans will be freed and reallocated.

			*/

			trans_pcie->scheduled_for_removal = true;



			removal->pdev = to_pci_dev(trans->dev);

			INIT_WORK(&removal->work, iwl_trans_pcie_removal_wk);

			pci_dev_get(removal->pdev);

			schedule_work(&removal->work);

		} else {

			iwl_write32(trans, CSR_RESET,

				    CSR_RESET_REG_FLAG_FORCE_NMI);

		}



err:

		spin_unlock_irqrestore(&trans_pcie->reg_lock, *flags);

		spin_unlock_irqrestore(&trans_pcie->reg_lock, *flags);

		return false;

		return false;

	}

	}