From 3733697cb7dd1ada4181affd1d170bdc47888bba Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Fri, 16 Feb 2024 16:09:28 -0800 Subject: [PATCH] xhci: Add helper to set an interrupters interrupt moderation interval [ 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 Signed-off-by: Wesley Cheng Link: https://lore.kernel.org/r/20240217001017.29969-3-quic_wcheng@quicinc.com Signed-off-by: Greg Kroah-Hartman Stable-dep-of: bea5892d0ed2 ("xhci: Limit time spent with xHC interrupts disabled during bus resume") Signed-off-by: Sasha Levin --- 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 5c3250989047..d6a0c79e5fad 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;