Hi Guenter,
On 5/4/25 16:00, Guenter Roeck wrote:
This series is needed to support the USB interface on imx8mp-evk when
booting the Linux kernel.
According to the XHCI specification, ERSTBA should be written in Low-High
order. The Linux kernel writes the high word first. This results in an
initialization failure.
The following information is found in the Linux kernel commit log.
[Synopsys]- The host controller was design to support ERST setting
during the RUN state. But since there is a limitation in controller
in supporting separate ERSTBA_HI and ERSTBA_LO programming,
It is supported when the ERSTBA is programmed in 64bit,
or in 32 bit mode ERSTBA_HI before ERSTBA_LO
[Synopsys]- The internal initialization of event ring fetches
the "Event Ring Segment Table Entry" based on the indication of
ERSTBA_LO written.
Add property to support writing the high word first. Enable it
for dwc3.
----------------------------------------------------------------
Guenter Roeck (2):
hw: usb: xhci: Add property to support writing ERSTBA in high-low order
hw/usb/hcd-dwc3: Set erstba-hi-lo property
What about using .impl.min_access_size = 8 instead?
Could you try this patch, or provide me with a reproducer?
-- >8 --
diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index 64c3a23b9b7..bce61a287bf 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -3043,7 +3043,4 @@ static uint64_t xhci_runtime_read(void *ptr,
hwaddr reg,
switch (reg & 0x1f) {
- case 0x00: /* IMAN */
- ret = intr->iman;
- break;
- case 0x04: /* IMOD */
- ret = intr->imod;
+ case 0x00: /* IMAN & IMOD */
+ ret = deposit64(intr->iman, 32, 32, intr->imod);
break;
@@ -3052,13 +3049,7 @@ static uint64_t xhci_runtime_read(void *ptr,
hwaddr reg,
break;
- case 0x10: /* ERSTBA low */
- ret = intr->erstba_low;
+ case 0x10: /* ERSTBA */
+ ret = deposit64(intr->erstba_low, 32, 32, intr->erstba_high);
break;
- case 0x14: /* ERSTBA high */
- ret = intr->erstba_high;
- break;
- case 0x18: /* ERDP low */
- ret = intr->erdp_low;
- break;
- case 0x1c: /* ERDP high */
- ret = intr->erdp_high;
+ case 0x18: /* ERDP */
+ ret = deposit64(intr->erdp_low, 32, 32, intr->erdp_high);
break;
@@ -3088,3 +3079,3 @@ static void xhci_runtime_write(void *ptr, hwaddr reg,
switch (reg & 0x1f) {
- case 0x00: /* IMAN */
+ case 0x00: /* IMAN & IMOD */
if (val & IMAN_IP) {
@@ -3094,23 +3085,19 @@ static void xhci_runtime_write(void *ptr, hwaddr
reg,
intr->iman |= val & IMAN_IE;
+ intr->imod = extract64(val, 32, 32);
xhci_intr_update(xhci, v);
break;
- case 0x04: /* IMOD */
- intr->imod = val;
- break;
case 0x08: /* ERSTSZ */
- intr->erstsz = val & 0xffff;
+ intr->erstsz = extract64(val, 0, 16);
break;
- case 0x10: /* ERSTBA low */
+ case 0x10: /* ERSTBA */
if (xhci->nec_quirks) {
/* NEC driver bug: it doesn't align this to 64 bytes */
- intr->erstba_low = val & 0xfffffff0;
+ intr->erstba_low = extract64(val, 4, 28);
} else {
- intr->erstba_low = val & 0xffffffc0;
+ intr->erstba_low = extract64(val, 6, 26);
}
- break;
- case 0x14: /* ERSTBA high */
- intr->erstba_high = val;
+ intr->erstba_high = extract64(val, 32, 32);
xhci_er_reset(xhci, v);
break;
- case 0x18: /* ERDP low */
+ case 0x18: /* ERDP */
if (val & ERDP_EHB) {
@@ -3128,5 +3115,3 @@ static void xhci_runtime_write(void *ptr, hwaddr reg,
}
- break;
- case 0x1c: /* ERDP high */
- intr->erdp_high = val;
+ intr->erdp_high = extract64(val, 32, 32);
break;
@@ -3216,2 +3201,3 @@ static const MemoryRegionOps xhci_runtime_ops = {
.write = xhci_runtime_write,
+ .impl.min_access_size = 8,
.valid.min_access_size = 4,
---
Regards,
Phil.
