ath9k_htc: Load firmware asynchronously

This patch modifies ath9k_htc to load the needed
firmware in an asynchronous manner, fixing timeouts
that were introduced with the new udev changes.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 101 insertions, 56 deletions

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 77c8ded8de57..f317515d8bf3 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -968,8 +968,7 @@ static void ath9k_hif_usb_dealloc_urbs(struct hif_device_usb *hif_dev)
         ath9k_hif_usb_dealloc_rx_urbs(hif_dev);
 }
 
-static int ath9k_hif_usb_download_fw(struct hif_device_usb *hif_dev,
-                                     u32 drv_info)
+static int ath9k_hif_usb_download_fw(struct hif_device_usb *hif_dev)
 {
         int transfer, err;
         const void *data = hif_dev->firmware->data;
@@ -1000,7 +999,7 @@ static int ath9k_hif_usb_download_fw(struct hif_device_usb *hif_dev,
         }
         kfree(buf);
 
-        if (IS_AR7010_DEVICE(drv_info))
+        if (IS_AR7010_DEVICE(hif_dev->usb_device_id->driver_info))
                 firm_offset = AR7010_FIRMWARE_TEXT;
         else
                 firm_offset = AR9271_FIRMWARE_TEXT;
@@ -1021,28 +1020,18 @@ static int ath9k_hif_usb_download_fw(struct hif_device_usb *hif_dev,
         return 0;
 }
 
-static int ath9k_hif_usb_dev_init(struct hif_device_usb *hif_dev, u32 drv_info)
+static int ath9k_hif_usb_dev_init(struct hif_device_usb *hif_dev)
 {
-        int ret, idx;
         struct usb_host_interface *alt = &hif_dev->interface->altsetting[0];
         struct usb_endpoint_descriptor *endp;
+        int ret, idx;
 
-        /* Request firmware */
-        ret = request_firmware(&hif_dev->firmware, hif_dev->fw_name,
-                               &hif_dev->udev->dev);
-        if (ret) {
-                dev_err(&hif_dev->udev->dev,
-                        "ath9k_htc: Firmware - %s not found\n", hif_dev->fw_name);
-                goto err_fw_req;
-        }
-
-        /* Download firmware */
-        ret = ath9k_hif_usb_download_fw(hif_dev, drv_info);
+        ret = ath9k_hif_usb_download_fw(hif_dev);
         if (ret) {
                 dev_err(&hif_dev->udev->dev,
                         "ath9k_htc: Firmware - %s download failed\n",
                         hif_dev->fw_name);
-                goto err_fw_download;
+                return ret;
         }
 
         /* On downloading the firmware to the target, the USB descriptor of EP4
@@ -1064,23 +1053,84 @@ static int ath9k_hif_usb_dev_init(struct hif_device_usb *hif_dev, u32 drv_info)
         if (ret) {
                 dev_err(&hif_dev->udev->dev,
                         "ath9k_htc: Unable to allocate URBs\n");
-                goto err_fw_download;
+                return ret;
         }
 
         return 0;
-
-err_fw_download:
-        release_firmware(hif_dev->firmware);
-err_fw_req:
-        hif_dev->firmware = NULL;
-        return ret;
 }
 
 static void ath9k_hif_usb_dev_deinit(struct hif_device_usb *hif_dev)
 {
         ath9k_hif_usb_dealloc_urbs(hif_dev);
-        if (hif_dev->firmware)
-                release_firmware(hif_dev->firmware);
+}
+
+/*
+ * If initialization fails or the FW cannot be retrieved,
+ * detach the device.
+ */
+static void ath9k_hif_usb_firmware_fail(struct hif_device_usb *hif_dev)
+{
+        struct device *parent = hif_dev->udev->dev.parent;
+
+        complete(&hif_dev->fw_done);
+
+        if (parent)
+                device_lock(parent);
+
+        device_release_driver(&hif_dev->udev->dev);
+
+        if (parent)
+                device_unlock(parent);
+}
+
+static void ath9k_hif_usb_firmware_cb(const struct firmware *fw, void *context)
+{
+        struct hif_device_usb *hif_dev = context;
+        int ret;
+
+        if (!fw) {
+                dev_err(&hif_dev->udev->dev,
+                        "ath9k_htc: Failed to get firmware %s\n",
+                        hif_dev->fw_name);
+                goto err_fw;
+        }
+
+        hif_dev->htc_handle = ath9k_htc_hw_alloc(hif_dev, &hif_usb,
+                                                 &hif_dev->udev->dev);
+        if (hif_dev->htc_handle == NULL) {
+                goto err_fw;
+        }
+
+        hif_dev->firmware = fw;
+
+        /* Proceed with initialization */
+
+        ret = ath9k_hif_usb_dev_init(hif_dev);
+        if (ret)
+                goto err_dev_init;
+
+        ret = ath9k_htc_hw_init(hif_dev->htc_handle,
+                                &hif_dev->interface->dev,
+                                hif_dev->usb_device_id->idProduct,
+                                hif_dev->udev->product,
+                                hif_dev->usb_device_id->driver_info);
+        if (ret) {
+                ret = -EINVAL;
+                goto err_htc_hw_init;
+        }
+
+        complete(&hif_dev->fw_done);
+
+        return;
+
+err_htc_hw_init:
+        ath9k_hif_usb_dev_deinit(hif_dev);
+err_dev_init:
+        ath9k_htc_hw_free(hif_dev->htc_handle);
+        release_firmware(fw);
+        hif_dev->firmware = NULL;
+err_fw:
+        ath9k_hif_usb_firmware_fail(hif_dev);
 }
 
 /*
@@ -1155,20 +1205,16 @@ static int ath9k_hif_usb_probe(struct usb_interface *interface,
         }
 
         usb_get_dev(udev);
+
         hif_dev->udev = udev;
         hif_dev->interface = interface;
-        hif_dev->device_id = id->idProduct;
+        hif_dev->usb_device_id = id;
 #ifdef CONFIG_PM
         udev->reset_resume = 1;
 #endif
         usb_set_intfdata(interface, hif_dev);
 
-        hif_dev->htc_handle = ath9k_htc_hw_alloc(hif_dev, &hif_usb,
-                                                 &hif_dev->udev->dev);
-        if (hif_dev->htc_handle == NULL) {
-                ret = -ENOMEM;
-                goto err_htc_hw_alloc;
-        }
+        init_completion(&hif_dev->fw_done);
 
         /* Find out which firmware to load */
 
@@ -1177,29 +1223,22 @@ static int ath9k_hif_usb_probe(struct usb_interface *interface,
         else
                 hif_dev->fw_name = FIRMWARE_AR9271;
 
-        ret = ath9k_hif_usb_dev_init(hif_dev, id->driver_info);
-        if (ret) {
-                ret = -EINVAL;
-                goto err_hif_init_usb;
-        }
-
-        ret = ath9k_htc_hw_init(hif_dev->htc_handle,
-                                &interface->dev, hif_dev->device_id,
-                                hif_dev->udev->product, id->driver_info);
+        ret = request_firmware_nowait(THIS_MODULE, true, hif_dev->fw_name,
+                                      &hif_dev->udev->dev, GFP_KERNEL,
+                                      hif_dev, ath9k_hif_usb_firmware_cb);
         if (ret) {
-                ret = -EINVAL;
-                goto err_htc_hw_init;
+                dev_err(&hif_dev->udev->dev,
+                        "ath9k_htc: Async request for firmware %s failed\n",
+                        hif_dev->fw_name);
+                goto err_fw_req;
         }
 
-        dev_info(&hif_dev->udev->dev, "ath9k_htc: USB layer initialized\n");
+        dev_info(&hif_dev->udev->dev, "ath9k_htc: Firmware %s requested\n",
+                 hif_dev->fw_name);
 
         return 0;
 
-err_htc_hw_init:
-        ath9k_hif_usb_dev_deinit(hif_dev);
-err_hif_init_usb:
-        ath9k_htc_hw_free(hif_dev->htc_handle);
-err_htc_hw_alloc:
+err_fw_req:
         usb_set_intfdata(interface, NULL);
         kfree(hif_dev);
         usb_put_dev(udev);
@@ -1234,9 +1273,15 @@ static void ath9k_hif_usb_disconnect(struct usb_interface *interface)
         if (!hif_dev)
                 return;
 
-        ath9k_htc_hw_deinit(hif_dev->htc_handle, unplugged);
-        ath9k_htc_hw_free(hif_dev->htc_handle);
-        ath9k_hif_usb_dev_deinit(hif_dev);
+        wait_for_completion(&hif_dev->fw_done);
+
+        if (hif_dev->firmware) {
+                ath9k_htc_hw_deinit(hif_dev->htc_handle, unplugged);
+                ath9k_htc_hw_free(hif_dev->htc_handle);
+                ath9k_hif_usb_dev_deinit(hif_dev);
+                release_firmware(hif_dev->firmware);
+        }
+
         usb_set_intfdata(interface, NULL);
 
         if (!unplugged && (hif_dev->flags & HIF_USB_START))
@@ -1276,8 +1321,7 @@ static int ath9k_hif_usb_resume(struct usb_interface *interface)
                 return ret;
 
         if (hif_dev->firmware) {
-                ret = ath9k_hif_usb_download_fw(hif_dev,
-                                htc_handle->drv_priv->ah->hw_version.usbdev);
+                ret = ath9k_hif_usb_download_fw(hif_dev);
                 if (ret)
                         goto fail_resume;
         } else {
diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.h b/drivers/net/wireless/ath/ath9k/hif_usb.h
index 794f63094e5d..487ff658b4c1 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.h
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.h
@@ -87,10 +87,11 @@ struct cmd_buf {
 #define HIF_USB_START BIT(0)
 
 struct hif_device_usb {
-        u16 device_id;
         struct usb_device *udev;
         struct usb_interface *interface;
+        const struct usb_device_id *usb_device_id;
         const struct firmware *firmware;
+        struct completion fw_done;
         struct htc_target *htc_handle;
         struct hif_usb_tx tx;
         struct usb_anchor regout_submitted;