6.6-stable review patch. If anyone has any objections, please let me know.
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From: Mathias Nyman mathias.nyman@linux.intel.com
[ Upstream commit ace21625878f78708b75b7a872ec7a0e2ed15ca4 ]
Add a helper to set the interrupt moderation interval for an interrupter. Each interrupter can have its own moderation value.
Hardware has a 16bit register for the moderation value, each step is 250ns.
Helper function imod_interval argument is in nanoseconds.
Values from 0 to 16383750 (250 x 0xffff) are accepted. 0 means no interrupt throttling.
Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Signed-off-by: Wesley Cheng quic_wcheng@quicinc.com Link: https://lore.kernel.org/r/20240217001017.29969-3-quic_wcheng@quicinc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Stable-dep-of: bea5892d0ed2 ("xhci: Limit time spent with xHC interrupts disabled during bus resume") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/host/xhci.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 5c3250989047e..d6a0c79e5fada 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -323,6 +323,23 @@ static int xhci_disable_interrupter(struct xhci_interrupter *ir) return 0; }
+/* interrupt moderation interval imod_interval in nanoseconds */ +static int xhci_set_interrupter_moderation(struct xhci_interrupter *ir, + u32 imod_interval) +{ + u32 imod; + + if (!ir || !ir->ir_set || imod_interval > U16_MAX * 250) + return -EINVAL; + + imod = readl(&ir->ir_set->irq_control); + imod &= ~ER_IRQ_INTERVAL_MASK; + imod |= (imod_interval / 250) & ER_IRQ_INTERVAL_MASK; + writel(imod, &ir->ir_set->irq_control); + + return 0; +} + static void compliance_mode_recovery(struct timer_list *t) { struct xhci_hcd *xhci; @@ -505,7 +522,6 @@ static int xhci_run_finished(struct xhci_hcd *xhci) */ int xhci_run(struct usb_hcd *hcd) { - u32 temp; u64 temp_64; int ret; struct xhci_hcd *xhci = hcd_to_xhci(hcd); @@ -525,12 +541,7 @@ int xhci_run(struct usb_hcd *hcd) xhci_dbg_trace(xhci, trace_xhci_dbg_init, "ERST deq = 64'h%0lx", (long unsigned int) temp_64);
- xhci_dbg_trace(xhci, trace_xhci_dbg_init, - "// Set the interrupt modulation register"); - temp = readl(&ir->ir_set->irq_control); - temp &= ~ER_IRQ_INTERVAL_MASK; - temp |= (xhci->imod_interval / 250) & ER_IRQ_INTERVAL_MASK; - writel(temp, &ir->ir_set->irq_control); + xhci_set_interrupter_moderation(ir, xhci->imod_interval);
if (xhci->quirks & XHCI_NEC_HOST) { struct xhci_command *command;