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Commit 1ed5a133 authored by Rupesh Tatiya's avatar Rupesh Tatiya
Browse files

Bluetooth: Protect request_firmware with a semaphore for btusb 



If btusb_probe gets called during system suspend/resume,
request_firmware call will fail sometimes as userspace processes
that help in request_firmware are frozen as a part of suspend.

Change-Id: I51c6fc0221e56e9dfa507aee0c26005e805a9e78
Signed-off-by: default avatarRupesh Tatiya <rtatiya@codeaurora.org>
parent f81d0b1f

drivers/bluetooth/ath3k.c

+9 −4
Original line number Diff line number Diff line
@@ -452,6 +452,9 @@ static int ath3k_set_normal_mode(struct usb_device *udev) 
			NULL, 0, USB_CTRL_SET_TIMEOUT);

}



DECLARE_RWSEM(btusb_pm_sem);

EXPORT_SYMBOL(btusb_pm_sem);



static int ath3k_load_patch(struct usb_device *udev,

						struct ath3k_version *version)

{
@@ -471,10 +474,9 @@ static int ath3k_load_patch(struct usb_device *udev, 


	if ((fw_state == ATH3K_PATCH_UPDATE) ||

		(fw_state == ATH3K_PATCH_SYSCFG_UPDATE)) {

		BT_INFO("%s: Patch already downloaded(fw_state: %d)", __func__,

			fw_state);

		BT_INFO("Patch already downloaded(fw_state: %d)", fw_state);

		return 0;

	}

	} else

		BT_DBG("Downloading RamPatch(fw_state: %d)", fw_state);



	switch (version->rom_version) {
@@ -497,11 +499,14 @@ static int ath3k_load_patch(struct usb_device *udev, 
		break;

	}



	down_read(&btusb_pm_sem);

	ret = request_firmware(&firmware, filename, &udev->dev);

	if (ret < 0) {

		BT_ERR("Patch file not found %s", filename);

		up_read(&btusb_pm_sem);

		return ret;

	}

	up_read(&btusb_pm_sem);



	if ((version->rom_version == ROME2_1_USB_CHIP_VERSION) ||

		(version->rom_version == ROME3_0_USB_CHIP_VERSION)) {

drivers/bluetooth/ath3k.h

+2 −0
Original line number Diff line number Diff line
@@ -25,3 +25,5 @@ struct ath3k_version { 
int get_rome_version(struct usb_device *udev, struct ath3k_version *version);

int rome_download(struct usb_device *udev, struct ath3k_version *version);



extern struct rw_semaphore btusb_pm_sem;

drivers/bluetooth/btusb.c

+49 −1
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/module.h>

#include <linux/usb.h>

#include <linux/firmware.h>

#include <linux/suspend.h>



#include <net/bluetooth/bluetooth.h>

#include <net/bluetooth/hci_core.h>
@@ -2295,6 +2296,29 @@ done: 
}

#endif



static unsigned long btusb_pm_flags;

#define BTUSB_PM_SUSPEND	(1)

static int btusb_pm_notify(struct notifier_block *b,

				unsigned long event, void *p)

{

	switch (event) {

	case PM_SUSPEND_PREPARE:

		set_bit(BTUSB_PM_SUSPEND, &btusb_pm_flags);

		down_write(&btusb_pm_sem);

		break;

	case PM_POST_SUSPEND:

		up_write(&btusb_pm_sem);

		clear_bit(BTUSB_PM_SUSPEND, &btusb_pm_flags);

		break;

	}



	return NOTIFY_DONE;

}



static struct notifier_block btusb_pm_notifier = {

	.notifier_call = btusb_pm_notify,

};



static struct usb_driver btusb_driver = {

	.name		= "btusb",

	.probe		= btusb_probe,
@@ -2308,7 +2332,31 @@ static struct usb_driver btusb_driver = { 
	.disable_hub_initiated_lpm = 1,

};



module_usb_driver(btusb_driver);

static int __init btusb_driver_init(void)

{

	int ret = 0;



	ret = usb_register(&btusb_driver);

	/* ignore return value */

	register_pm_notifier(&btusb_pm_notifier);

	return ret;

}

module_init(btusb_driver_init);



static void __exit btusb_driver_exit(void)

{

	unregister_pm_notifier(&btusb_pm_notifier);

	/*

	 * If unregister gets called before resume notification, we need to

	 * release the semaphore to avoid deadlock.

	 */

	if (test_bit(BTUSB_PM_SUSPEND, &btusb_pm_flags)) {

		up_write(&btusb_pm_sem);

		clear_bit(BTUSB_PM_SUSPEND, &btusb_pm_flags);

	}

	usb_deregister(&btusb_driver);

}

module_exit(btusb_driver_exit);



module_param(disable_scofix, bool, 0644);

MODULE_PARM_DESC(disable_scofix, "Disable fixup of wrong SCO buffer size");