xusb: Increase performance up to 96%

The default interrupt moderation on XUSB controller was causing 4.62ms latency, hurting performance tremendously, especially in smaller usb packets (which are the norm).
This change brings it to parity with USB2 controller.
This commit is contained in:
CTCaer
2020-12-30 13:40:16 +02:00
parent 4949331f4c
commit b7789f1edb
2 changed files with 8 additions and 3 deletions

View File

@@ -895,14 +895,11 @@ int xusb_device_init()
XUSB_DEV_DEV(XUSB_DEV_INTR_MASK) |= DEV_INTR_MASK_IP_INT_MASK;
// AHB USB performance cfg.
//TODO: Doesn't help..
/*
AHB_GIZMO(AHB_GIZMO_AHB_MEM) |= AHB_MEM_DONT_SPLIT_AHB_WR | AHB_MEM_ENB_FAST_REARBITRATE;
AHB_GIZMO(AHB_GIZMO_USB3) |= AHB_GIZMO_IMMEDIATE;
AHB_GIZMO(AHB_ARBITRATION_PRIORITY_CTRL) = PRIORITY_CTRL_WEIGHT(7) | PRIORITY_SELECT_USB3;
AHB_GIZMO(AHB_AHB_MEM_PREFETCH_CFG1) =
MEM_PREFETCH_ENABLE | MEM_PREFETCH_USB3_MST_ID | MEM_PREFETCH_ADDR_BNDRY(12) | 0x1000; // Addr boundary 64KB, Inactivity 4096 cycles.
*/
// Initialize context.
usbd_xotg = &usbd_xotg_controller_ctxt;
@@ -1771,6 +1768,13 @@ int xusb_device_enumerate(usb_gadget_type gadget)
usbd_xotg->gadget = gadget;
/*
* Set interrupt moderation to 0us.
* This is important because default value creates a 4.62ms latency.
* Effectively hurting transfers by having 15% to 96% performance loss.
*/
XUSB_DEV_XHCI(XUSB_DEV_XHCI_RT_IMOD) = 0;
// Disable Wake events.
XUSB_PADCTL(XUSB_PADCTL_ELPG_PROGRAM_0) = 0;
XUSB_PADCTL(XUSB_PADCTL_ELPG_PROGRAM_1) = 0;