Am 16. Juli 2025 20:07:25 UTC schrieb Guenter Roeck <li...@roeck-us.net>:
>On Wed, Jul 16, 2025 at 07:59:16PM +0000, Bernhard Beschow wrote:
>>
>>
>> Am 13. April 2025 16:03:16 UTC schrieb Guenter Roeck <li...@roeck-us.net>:
>> >On 4/11/25 00:40, Nicholas Piggin wrote:
>> >> On Sun Apr 6, 2025 at 12:00 AM AEST, Guenter Roeck wrote:
>> >>> 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.
>> >>
>> >> This should probably be reworded, it's not so much that Linux does it,
>> >> this kind of implies a Linux bug. It is that the hardware requires it
>> >> and Linux works around such quirk.
>> >>
>> >> According to the XHCI specification, ERSTBA should be written in
>> >> Low-High
>> >> order, however some controllers have a quirk that requires the low
>> >> word to be written last.
>> >>
>> >>>
>> >>> 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.
>> >>
>> >> Could you include a reference to the commit in the normal form?
>> >>
>> >> The following information is found in the changelog for Linux kernel
>> >> commit sha ("blah").
>> >>
>> >>>
>> >>> Add property to support writing the high word first.
>> >>>
>> >>> Signed-off-by: Guenter Roeck <li...@roeck-us.net>
>> >>> ---
>> >>> hw/usb/hcd-xhci.c | 8 +++++++-
>> >>> hw/usb/hcd-xhci.h | 1 +
>> >>> 2 files changed, 8 insertions(+), 1 deletion(-)
>> >>>
>> >>> diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
>> >>> index 64c3a23b9b..8c0ba569c8 100644
>> >>> --- a/hw/usb/hcd-xhci.c
>> >>> +++ b/hw/usb/hcd-xhci.c
>> >>> @@ -3107,10 +3107,15 @@ static void xhci_runtime_write(void *ptr, hwaddr
>> >>> reg,
>> >>> } else {
>> >>> intr->erstba_low = val & 0xffffffc0;
>> >>> }
>> >>> + if (xhci->erstba_hi_lo) {
>> >>> + xhci_er_reset(xhci, v);
>> >>> + }
>> >>> break;
>> >>> case 0x14: /* ERSTBA high */
>> >>> intr->erstba_high = val;
>> >>> - xhci_er_reset(xhci, v);
>> >>> + if (!xhci->erstba_hi_lo) {
>> >>> + xhci_er_reset(xhci, v);
>> >>> + }
>> >>> break;
>> >>> case 0x18: /* ERDP low */
>> >>> if (val & ERDP_EHB) {
>> >>> @@ -3636,6 +3641,7 @@ static const Property xhci_properties[] = {
>> >>> DEFINE_PROP_UINT32("p3", XHCIState, numports_3, 4),
>> >>> DEFINE_PROP_LINK("host", XHCIState, hostOpaque, TYPE_DEVICE,
>> >>> DeviceState *),
>> >>> + DEFINE_PROP_BOOL("erstba-hi-lo", XHCIState, erstba_hi_lo, false),
>> >>> };
>> >>> static void xhci_class_init(ObjectClass *klass, void *data)
>> >>> diff --git a/hw/usb/hcd-xhci.h b/hw/usb/hcd-xhci.h
>> >>> index 9c3974f148..cf3f074261 100644
>> >>> --- a/hw/usb/hcd-xhci.h
>> >>> +++ b/hw/usb/hcd-xhci.h
>> >>> @@ -189,6 +189,7 @@ typedef struct XHCIState {
>> >>> uint32_t numports_3;
>> >>> uint32_t numintrs;
>> >>> uint32_t numslots;
>> >>> + bool erstba_hi_lo;
>> >>
>> >> Could you use the "quirk" prefix for the device and property name?
>> >>
>> >
>> >Done all, except then I noticed that you want me to prepend "quirk"
>> >and I appended it out of habit. So I'll need to start over :-(.
>>
>> Ping
>>
>> Any news? Would be nice if a fix made it into 10.1.
>>
>
>Sorry, I ran out of time and won't be able to look into this again
>anytime soon. I don't mind if someone else wants to pick it up.
Okay, I will look into it as soon as I find some time.
Bernhard
>
>Guenter
