Author: hselasky
Date: Mon Jun 8 09:27:48 2020
New Revision: 361911
URL: https://svnweb.freebsd.org/changeset/base/361911
Log:
MFC r361581:
Implement helper function, usbd_get_max_frame_length(), which allows kernel
device drivers to correctly predict the default USB transfer frame length.
Sponsored by: Mellanox Technologies
Modified:
stable/11/sys/dev/usb/usb_transfer.c
stable/11/sys/dev/usb/usbdi.h
Directory Properties:
stable/11/ (props changed)
Modified: stable/11/sys/dev/usb/usb_transfer.c
==============================================================================
--- stable/11/sys/dev/usb/usb_transfer.c Mon Jun 8 09:26:46 2020
(r361910)
+++ stable/11/sys/dev/usb/usb_transfer.c Mon Jun 8 09:27:48 2020
(r361911)
@@ -373,6 +373,81 @@ usbd_transfer_setup_sub_malloc(struct usb_setup_params
#endif
/*------------------------------------------------------------------------*
+ * usbd_get_max_frame_length
+ *
+ * This function returns the maximum single frame length as computed by
+ * usbd_transfer_setup(). It is useful when computing buffer sizes for
+ * devices having multiple alternate settings. The SuperSpeed endpoint
+ * companion pointer is allowed to be NULL.
+ *------------------------------------------------------------------------*/
+uint32_t
+usbd_get_max_frame_length(const struct usb_endpoint_descriptor *edesc,
+ const struct usb_endpoint_ss_comp_descriptor *ecomp,
+ enum usb_dev_speed speed)
+{
+ uint32_t max_packet_size;
+ uint32_t max_packet_count;
+ uint8_t type;
+
+ max_packet_size = UGETW(edesc->wMaxPacketSize);
+ max_packet_count = 1;
+ type = (edesc->bmAttributes & UE_XFERTYPE);
+
+ switch (speed) {
+ case USB_SPEED_HIGH:
+ switch (type) {
+ case UE_ISOCHRONOUS:
+ case UE_INTERRUPT:
+ max_packet_count +=
+ (max_packet_size >> 11) & 3;
+
+ /* check for invalid max packet count */
+ if (max_packet_count > 3)
+ max_packet_count = 3;
+ break;
+ default:
+ break;
+ }
+ max_packet_size &= 0x7FF;
+ break;
+ case USB_SPEED_SUPER:
+ max_packet_count += (max_packet_size >> 11) & 3;
+
+ if (ecomp != NULL)
+ max_packet_count += ecomp->bMaxBurst;
+
+ if ((max_packet_count == 0) ||
+ (max_packet_count > 16))
+ max_packet_count = 16;
+
+ switch (type) {
+ case UE_CONTROL:
+ max_packet_count = 1;
+ break;
+ case UE_ISOCHRONOUS:
+ if (ecomp != NULL) {
+ uint8_t mult;
+
+ mult = UE_GET_SS_ISO_MULT(
+ ecomp->bmAttributes) + 1;
+ if (mult > 3)
+ mult = 3;
+
+ max_packet_count *= mult;
+ }
+ break;
+ default:
+ break;
+ }
+ max_packet_size &= 0x7FF;
+ break;
+ default:
+ break;
+ }
+ return (max_packet_size * max_packet_count);
+}
+
+/*------------------------------------------------------------------------*
* usbd_transfer_setup_sub - transfer setup subroutine
*
* This function must be called from the "xfer_setup" callback of the
Modified: stable/11/sys/dev/usb/usbdi.h
==============================================================================
--- stable/11/sys/dev/usb/usbdi.h Mon Jun 8 09:26:46 2020
(r361910)
+++ stable/11/sys/dev/usb/usbdi.h Mon Jun 8 09:27:48 2020
(r361911)
@@ -552,6 +552,9 @@ uint8_t usbd_get_interface_altindex(struct usb_interfa
usb_error_t usbd_set_alt_interface_index(struct usb_device *udev,
uint8_t iface_index, uint8_t alt_index);
uint32_t usbd_get_isoc_fps(struct usb_device *udev);
+uint32_t usbd_get_max_frame_length(const struct usb_endpoint_descriptor *,
+ const struct usb_endpoint_ss_comp_descriptor *,
+ enum usb_dev_speed);
usb_error_t usbd_transfer_setup(struct usb_device *udev,
const uint8_t *ifaces, struct usb_xfer **pxfer,
const struct usb_config *setup_start, uint16_t n_setup,
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