[PATCH v2 4/5] xhci: Add a quirk for writing ERST in high-low order

Daehwan Jung
2024-05-31T06:07:33Z

This quirk is for the controller that has a limitation in supporting
separate ERSTBA_HI and ERSTBA_LO programming. It's supported when
the ERSTBA is programmed ERSTBA_HI before ERSTBA_LO. That's because
the internal initialization of event ring fetches the
"Event Ring Segment Table Entry" based on the indication of ERSTBA_LO
written.

Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
---
RFC -> v1:
- add a quirk in xhci
- use the quirk for programming ERST high-low order
---
drivers/usb/host/xhci-mem.c | 5 ++++-
drivers/usb/host/xhci.h | 2 ++
2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 3100219..ef768e6 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2325,7 +2325,10 @@ xhci_add_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir,
erst_base = xhci_read_64(xhci, &ir->ir_set->erst_base);
erst_base &= ERST_BASE_RSVDP;
erst_base |= ir->erst.erst_dma_addr & ~ERST_BASE_RSVDP;
- xhci_write_64(xhci, erst_base, &ir->ir_set->erst_base);
+ if (xhci->quirks & XHCI_WRITE_64_HI_LO)
+ hi_lo_writeq(erst_base, &ir->ir_set->erst_base);
+ else
+ xhci_write_64(xhci, erst_base, &ir->ir_set->erst_base);

/* Set the event ring dequeue address of this interrupter */
xhci_set_hc_event_deq(xhci, ir);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 3041515..8664dd1 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -17,6 +17,7 @@
#include <linux/kernel.h>
#include <linux/usb/hcd.h>
#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/io-64-nonatomic-hi-lo.h>

/* Code sharing between pci-quirks and xhci hcd */
#include "xhci-ext-caps.h"
@@ -1627,6 +1628,7 @@ struct xhci_hcd {
#define XHCI_RESET_TO_DEFAULT BIT_ULL(44)
#define XHCI_ZHAOXIN_TRB_FETCH BIT_ULL(45)
#define XHCI_ZHAOXIN_HOST BIT_ULL(46)
+#define XHCI_WRITE_64_HI_LO BIT_ULL(47)

unsigned int num_active_eps;
unsigned int limit_active_eps;
--
2.7.4