Hi Mathias,
On 5/2/2024 4:07 AM, Mathias Nyman wrote:
On 26.4.2024 0.50, Wesley Cheng wrote:
Some use cases maybe require that the secondary interrupter's events to be handled by the OS. In this case, configure the IMOD and the skip_events property to enable the interrupter's events. By default, assume that the secondary interrupter doesn't want to enable OS event handling.
Signed-off-by: Wesley Cheng quic_wcheng@quicinc.com
drivers/usb/host/xhci-sideband.c | 28 ++++++++++++++++++++++++++++ include/linux/usb/xhci-sideband.h | 2 ++ 2 files changed, 30 insertions(+)
diff --git a/drivers/usb/host/xhci-sideband.c b/drivers/usb/host/xhci-sideband.c index 255feae33c6e..6fdae9840c11 100644 --- a/drivers/usb/host/xhci-sideband.c +++ b/drivers/usb/host/xhci-sideband.c @@ -237,6 +237,30 @@ xhci_sideband_get_event_buffer(struct xhci_sideband *sb) } EXPORT_SYMBOL_GPL(xhci_sideband_get_event_buffer); +/**
- xhci_sideband_enable_interrupt - enable interrupt for secondary
interrupter
- @sb: sideband instance for this usb device
- @imod_interval: number of event ring segments to allocate
- Enables OS owned event handling for a particular interrupter if
client
- requests for it. In addition, set the IMOD interval for this
particular
- interrupter.
- Returns 0 on success, negative error otherwise
- */
+int xhci_sideband_enable_interrupt(struct xhci_sideband *sb, u32 imod_interval) +{ + if (!sb || !sb->ir) + return -ENODEV;
+ xhci_set_interrupter_moderation(sb->ir, imod_interval);
Is there a need to adjust the moderation after initial setup?
If not then maybe we could pass the imod_interval as a parameter to xhci_create_secondary_interrupter(), and avoid exporting xhci_set_interrupter_moderation()
Let me preface my comments by saying that I was trying to include some aspects of enabling the secondary interrupter line within the main apps proc. If this gets too confusing, I can remove these mechanisms for now. For example, as you mentioned below xhci_sideband_enable_interrupt() isn't going to be used in the offload path.
However, I decided to add it so we can have some corresponding function that will utilize/set skip_events = false. (as it is "true" by default) Again, I can remove this part and revisit later when we actually have a use case to handle secondary interrupts on apps.
As for the IMOD setting, depending on what you think, I can add it as part of xhci_create_secondary_interrupter()
+ sb->ir->skip_events = false; + xhci_enable_interrupter(sb->ir);
+ return 0; +} +EXPORT_SYMBOL_GPL(xhci_sideband_enable_interrupt);
I can't find the place where xhci_sideband_enable_interrupt() is called in this series. How is it planned to be used?
Thanks Mathias
Thanks Wesley Cheng