From: Mathias Nyman mathias.nyman@linux.intel.com
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 --- 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 0886829d53e5..b405b8236134 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -346,6 +346,23 @@ 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; @@ -528,7 +545,6 @@ 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); @@ -551,12 +567,7 @@ 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;