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xhci: Add helper to set an interrupters interrupt moderation interval

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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>
This commit is contained in:
Mathias Nyman 2024-02-16 16:09:28 -08:00 committed by Greg Kroah-Hartman
parent 4f022aad80
commit ace2162587
1 changed files with 18 additions and 7 deletions
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25
drivers/usb/host/xhci.c
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@ -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;