[PATCH v3 2/2] usb: host: xhci-sideband: delegate offload_usage tracking to class drivers

[Guan-Yu Lin <guanyulin@google.com>]

Remove usb_offload_get() and usb_offload_put() from the xHCI sideband
interrupter creation and removal paths.

The responsibility of manipulating offload_usage now lies entirely with
the USB class drivers. They have the precise context of when an offload
data stream actually starts and stops, ensuring a much more accurate
representation of offload activity for power management.

Cc: stable@vger.kernel.org
Fixes: ef82a4803aab ("xhci: sideband: add api to trace sideband usage")
Signed-off-by: Guan-Yu Lin <guanyulin@google.com>
---
 drivers/usb/host/xhci-sideband.c  | 14 +-------------
 sound/usb/qcom/qc_audio_offload.c | 10 +++++++++-
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/host/xhci-sideband.c b/drivers/usb/host/xhci-sideband.c
index 1ddb64b0a48e..651973606137 100644
--- a/drivers/usb/host/xhci-sideband.c
+++ b/drivers/usb/host/xhci-sideband.c
@@ -93,8 +93,6 @@ __xhci_sideband_remove_endpoint(struct xhci_sideband *sb, struct xhci_virt_ep *e
 static void
 __xhci_sideband_remove_interrupter(struct xhci_sideband *sb)
 {
-	struct usb_device *udev;
-
 	lockdep_assert_held(&sb->mutex);
 
 	if (!sb->ir)
@@ -102,10 +100,6 @@ __xhci_sideband_remove_interrupter(struct xhci_sideband *sb)
 
 	xhci_remove_secondary_interrupter(xhci_to_hcd(sb->xhci), sb->ir);
 	sb->ir = NULL;
-	udev = sb->vdev->udev;
-
-	if (udev->state != USB_STATE_NOTATTACHED)
-		usb_offload_put(udev);
 }
 
 /* sideband api functions */
@@ -328,9 +322,6 @@ int
 xhci_sideband_create_interrupter(struct xhci_sideband *sb, int num_seg,
 				 bool ip_autoclear, u32 imod_interval, int intr_num)
 {
-	int ret = 0;
-	struct usb_device *udev;
-
 	if (!sb || !sb->xhci)
 		return -ENODEV;
 
@@ -348,12 +339,9 @@ xhci_sideband_create_interrupter(struct xhci_sideband *sb, int num_seg,
 	if (!sb->ir)
 		return -ENOMEM;
 
-	udev = sb->vdev->udev;
-	ret = usb_offload_get(udev);
-
 	sb->ir->ip_autoclear = ip_autoclear;
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(xhci_sideband_create_interrupter);
 
diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
index cfb30a195364..abafbc78dea9 100644
--- a/sound/usb/qcom/qc_audio_offload.c
+++ b/sound/usb/qcom/qc_audio_offload.c
@@ -699,6 +699,7 @@ static void uaudio_event_ring_cleanup_free(struct uaudio_dev *dev)
 		uaudio_iommu_unmap(MEM_EVENT_RING, IOVA_BASE, PAGE_SIZE,
 				   PAGE_SIZE);
 		xhci_sideband_remove_interrupter(uadev[dev->chip->card->number].sb);
+		usb_offload_put(dev->udev);
 	}
 }
 
@@ -1182,12 +1183,16 @@ static int uaudio_event_ring_setup(struct snd_usb_substream *subs,
 	dma_coherent = dev_is_dma_coherent(subs->dev->bus->sysdev);
 	er_pa = 0;
 
+	ret = usb_offload_get(subs->dev);
+	if (ret < 0)
+		goto exit;
+
 	/* event ring */
 	ret = xhci_sideband_create_interrupter(uadev[card_num].sb, 1, false,
 					       0, uaudio_qdev->data->intr_num);
 	if (ret < 0) {
 		dev_err(&subs->dev->dev, "failed to fetch interrupter\n");
-		goto exit;
+		goto put_offload;
 	}
 
 	sgt = xhci_sideband_get_event_buffer(uadev[card_num].sb);
@@ -1219,6 +1224,8 @@ static int uaudio_event_ring_setup(struct snd_usb_substream *subs,
 	mem_info->dma = 0;
 remove_interrupter:
 	xhci_sideband_remove_interrupter(uadev[card_num].sb);
+put_offload:
+	usb_offload_put(subs->dev);
 exit:
 	return ret;
 }
@@ -1483,6 +1490,7 @@ static int prepare_qmi_response(struct snd_usb_substream *subs,
 	uaudio_iommu_unmap(MEM_EVENT_RING, IOVA_BASE, PAGE_SIZE, PAGE_SIZE);
 free_sec_ring:
 	xhci_sideband_remove_interrupter(uadev[card_num].sb);
+	usb_offload_put(subs->dev);
 drop_sync_ep:
 	if (subs->sync_endpoint) {
 		uaudio_iommu_unmap(MEM_XFER_RING,
-- 
2.53.0.1018.g2bb0e51243-goog