wireless: ath9k-htc: only load firmware in need

It is not necessary to hold the firmware memory during the whole
driver lifetime, and obviously it does waste memory. Suppose there
are 4 ath9k-htc usb dongles working, kernel has to consume about
4*50KBytes RAM to cache firmware for all dongles. After applying the
patch, kernel only caches one single firmware image in RAM for
all ath9k-htc devices just during system suspend/resume cycle.

When system is ready for loading firmware, ath9k-htc can request
the loading from usersapce. During system resume, ath9k-htc still
can load the firmware which was cached in kernel memory before
system suspend.

Cc: ath9k-devel@lists.ath9k.org
Cc: "Luis R. Rodriguez" <mcgrof@qca.qualcomm.com>
Cc: Jouni Malinen <jouni@qca.qualcomm.com>
Cc: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Cc: Senthil Balasubramanian <senthilb@qca.qualcomm.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index aa327adcc3d8ffdf09261884580914ab41556ade..ee6e50aebf8d3fe997803262d3dd9d6b80ff1277 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -973,8 +973,8 @@ static void ath9k_hif_usb_dealloc_urbs(struct hif_device_usb *hif_dev)
 static int ath9k_hif_usb_download_fw(struct hif_device_usb *hif_dev)
 {
        int transfer, err;
-       const void *data = hif_dev->firmware->data;
-       size_t len = hif_dev->firmware->size;
+       const void *data = hif_dev->fw_data;
+       size_t len = hif_dev->fw_size;
        u32 addr = AR9271_FIRMWARE;
        u8 *buf = kzalloc(4096, GFP_KERNEL);
        u32 firm_offset;
@@ -1017,7 +1017,7 @@ static int ath9k_hif_usb_download_fw(struct hif_device_usb *hif_dev)
                return -EIO;
 
        dev_info(&hif_dev->udev->dev, "ath9k_htc: Transferred FW: %s, size: %ld\n",
-                hif_dev->fw_name, (unsigned long) hif_dev->firmware->size);
+                hif_dev->fw_name, (unsigned long) hif_dev->fw_size);
 
        return 0;
 }
@@ -1099,11 +1099,11 @@ static void ath9k_hif_usb_firmware_cb(const struct firmware *fw, void *context)
 
        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;
-       }
+       if (hif_dev->htc_handle == NULL)
+               goto err_dev_alloc;
 
-       hif_dev->firmware = fw;
+       hif_dev->fw_data = fw->data;
+       hif_dev->fw_size = fw->size;
 
        /* Proceed with initialization */
 
@@ -1121,6 +1121,8 @@ static void ath9k_hif_usb_firmware_cb(const struct firmware *fw, void *context)
                goto err_htc_hw_init;
        }
 
+       release_firmware(fw);
+       hif_dev->flags |= HIF_USB_READY;
        complete(&hif_dev->fw_done);
 
        return;
@@ -1129,8 +1131,8 @@ err_htc_hw_init:
        ath9k_hif_usb_dev_deinit(hif_dev);
 err_dev_init:
        ath9k_htc_hw_free(hif_dev->htc_handle);
+err_dev_alloc:
        release_firmware(fw);
-       hif_dev->firmware = NULL;
 err_fw:
        ath9k_hif_usb_firmware_fail(hif_dev);
 }
@@ -1277,11 +1279,10 @@ static void ath9k_hif_usb_disconnect(struct usb_interface *interface)
 
        wait_for_completion(&hif_dev->fw_done);
 
-       if (hif_dev->firmware) {
+       if (hif_dev->flags & HIF_USB_READY) {
                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);
@@ -1317,13 +1318,23 @@ static int ath9k_hif_usb_resume(struct usb_interface *interface)
        struct hif_device_usb *hif_dev = usb_get_intfdata(interface);
        struct htc_target *htc_handle = hif_dev->htc_handle;
        int ret;
+       const struct firmware *fw;
 
        ret = ath9k_hif_usb_alloc_urbs(hif_dev);
        if (ret)
                return ret;
 
-       if (hif_dev->firmware) {
+       if (hif_dev->flags & HIF_USB_READY) {
+               /* request cached firmware during suspend/resume cycle */
+               ret = request_firmware(&fw, hif_dev->fw_name,
+                                      &hif_dev->udev->dev);
+               if (ret)
+                       goto fail_resume;
+
+               hif_dev->fw_data = fw->data;
+               hif_dev->fw_size = fw->size;
                ret = ath9k_hif_usb_download_fw(hif_dev);
+               release_firmware(fw);
                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 487ff658b4c1890f597045c739d919ff6dd16689..51496e74b83eaf3521230421f3a07350c385e3d4 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/hif_usb.h
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.h
@@ -85,12 +85,14 @@ struct cmd_buf {
 };
 
 #define HIF_USB_START BIT(0)
+#define HIF_USB_READY BIT(1)
 
 struct hif_device_usb {
        struct usb_device *udev;
        struct usb_interface *interface;
        const struct usb_device_id *usb_device_id;
-       const struct firmware *firmware;
+       const void *fw_data;
+       size_t fw_size;
        struct completion fw_done;
        struct htc_target *htc_handle;
        struct hif_usb_tx tx;