openwrt/target/linux/bcm27xx/patches-5.15/950-0166-xhci-Use-more-event-ring-segment-table-entries.patch
John Audia a34255b795 kernel: bump 5.15 to 5.15.75
Removed upstreamed:
   bcm27xx/patches-5.15/950-0446-drm-vc4-Fix-timings-for-VEC-modes.patch[1]

Manually rebased:
   patches-5.15/950-0600-xhci-quirks-add-link-TRB-quirk-for-VL805.patch
   bcm27xx/patches-5.15/950-0606-usb-xhci-add-VLI_TRB_CACHE_BUG-quirk.patch
   bcm27xx/patches-5.15/950-0717-usb-xhci-add-a-quirk-for-Superspeed-bulk-OUT-transfe.patch
   bcm53xx/patches-5.15/180-usb-xhci-add-support-for-performing-fake-doorbell.patch

All other patches automatically rebased

1. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v5.15.75&id=2810061452f9b748b096ad023d318690ca519aa3

Build system: x86_64
Build-tested: bcm2711/RPi4B, mt7622/RT3200
Run-tested: bcm2711/RPi4B, mt7622/RT3200

Signed-off-by: John Audia <therealgraysky@proton.me>
2022-10-30 17:54:59 +01:00

61 lines
2.5 KiB
Diff

From 271d837c58918de2cac5715798ebf71df43b39f7 Mon Sep 17 00:00:00 2001
From: Jonathan Bell <jonathan@raspberrypi.org>
Date: Tue, 13 Aug 2019 15:53:29 +0100
Subject: [PATCH] xhci: Use more event ring segment table entries
Users have reported log spam created by "Event Ring Full" xHC event
TRBs. These are caused by interrupt latency in conjunction with a very
busy set of devices on the bus. The errors are benign, but throughput
will suffer as the xHC will pause processing of transfers until the
event ring is drained by the kernel. Expand the number of event TRB slots
available by increasing the number of event ring segments in the ERST.
Controllers have a hardware-defined limit as to the number of ERST
entries they can process, so make the actual number in use
min(ERST_MAX_SEGS, hw_max).
Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>
---
drivers/usb/host/xhci-mem.c | 8 +++++---
drivers/usb/host/xhci.h | 4 ++--
2 files changed, 7 insertions(+), 5 deletions(-)
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2516,9 +2516,11 @@ int xhci_mem_init(struct xhci_hcd *xhci,
* Event ring setup: Allocate a normal ring, but also setup
* the event ring segment table (ERST). Section 4.9.3.
*/
+ val2 = 1 << HCS_ERST_MAX(xhci->hcs_params2);
+ val2 = min_t(unsigned int, ERST_MAX_SEGS, val2);
xhci_dbg_trace(xhci, trace_xhci_dbg_init, "// Allocating event ring");
- xhci->event_ring = xhci_ring_alloc(xhci, ERST_NUM_SEGS, 1, TYPE_EVENT,
- 0, flags);
+ xhci->event_ring = xhci_ring_alloc(xhci, val2, 1, TYPE_EVENT,
+ 0, flags);
if (!xhci->event_ring)
goto fail;
if (xhci_check_trb_in_td_math(xhci) < 0)
@@ -2531,7 +2533,7 @@ int xhci_mem_init(struct xhci_hcd *xhci,
/* set ERST count with the number of entries in the segment table */
val = readl(&xhci->ir_set->erst_size);
val &= ERST_SIZE_MASK;
- val |= ERST_NUM_SEGS;
+ val |= val2;
xhci_dbg_trace(xhci, trace_xhci_dbg_init,
"// Write ERST size = %i to ir_set 0 (some bits preserved)",
val);
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1673,8 +1673,8 @@ struct urb_priv {
* Each segment table entry is 4*32bits long. 1K seems like an ok size:
* (1K bytes * 8bytes/bit) / (4*32 bits) = 64 segment entries in the table,
* meaning 64 ring segments.
- * Initial allocated size of the ERST, in number of entries */
-#define ERST_NUM_SEGS 1
+ * Maximum number of segments in the ERST */
+#define ERST_MAX_SEGS 8
/* Poll every 60 seconds */
#define POLL_TIMEOUT 60
/* Stop endpoint command timeout (secs) for URB cancellation watchdog timer */