diff options
| author | Adam Wallis <awallis@codeaurora.org> | 2017-12-08 18:59:13 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-08 19:43:52 +0300 |
| commit | ab725cbec3e83dc29cc00b733bd26063b588fa98 (patch) | |
| tree | 9466ec276003810875ae7e896031c038ed8a8fff /drivers/usb/host/xhci.c | |
| parent | 3054ea45fb8758b7c1a4849001e213e1267452fa (diff) | |
| download | linux-ab725cbec3e83dc29cc00b733bd26063b588fa98.tar.xz | |
usb: xhci: allow imod-interval to be configurable
The xHCI driver currently has the IMOD set to 160, which
translates to an IMOD interval of 40,000ns (160 * 250)ns
Commit 0cbd4b34cda9 ("xhci: mediatek: support MTK xHCI host controller")
introduced a QUIRK for the MTK platform to adjust this interval to 20,
which translates to an IMOD interval of 5,000ns (20 * 250)ns. This is
due to the fact that the MTK controller IMOD interval is 8 times
as much as defined in xHCI spec.
Instead of adding more quirk bits for additional platforms, this patch
introduces the ability for vendors to set the IMOD_INTERVAL as is
optimal for their platform. By using device_property_read_u32() on
"imod-interval-ns", the IMOD INTERVAL can be specified in nano seconds.
If no interval is specified, the default of 40,000ns (IMOD=160) will be
used.
No bounds checking has been implemented due to the fact that a vendor
may have violated the spec and would need to specify a value outside of
the max 8,000 IRQs/second limit specified in the xHCI spec.
Tested-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Adam Wallis <awallis@codeaurora.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/xhci.c')
| -rw-r--r-- | drivers/usb/host/xhci.c | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 060e5b446902..05104bd2b611 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -583,11 +583,7 @@ int xhci_run(struct usb_hcd *hcd) "// Set the interrupt modulation register"); temp = readl(&xhci->ir_set->irq_control); temp &= ~ER_IRQ_INTERVAL_MASK; - /* - * the increment interval is 8 times as much as that defined - * in xHCI spec on MTK's controller - */ - temp |= (u32) ((xhci->quirks & XHCI_MTK_HOST) ? 20 : 160); + temp |= (xhci->imod_interval / 250) & ER_IRQ_INTERVAL_MASK; writel(temp, &xhci->ir_set->irq_control); /* Set the HCD state before we enable the irqs */ |