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| author | Peter Chen <peter.chen@nxp.com> | 2017-05-17 17:32:02 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-18 15:19:41 +0200 |
| commit | 6a29beef9d1b16c762e469d77e28c3de3f5c3dbb (patch) | |
| tree | 4b2f2bfa6240cd2bcf1f2d69ff14a04aee80c987 /drivers/misc | |
| parent | usb: host: xhci-mem: allocate zeroed Scratchpad Buffer (diff) | |
| download | linux-6a29beef9d1b16c762e469d77e28c3de3f5c3dbb.tar.xz linux-6a29beef9d1b16c762e469d77e28c3de3f5c3dbb.zip | |
usb: host: xhci-ring: don't need to clear interrupt pending for MSI enabled hcd
According to xHCI spec Figure 30: Interrupt Throttle Flow Diagram
If PCI Message Signaled Interrupts (MSI or MSI-X) are enabled,
then the assertion of the Interrupt Pending (IP) flag in Figure 30
generates a PCI Dword write. The IP flag is automatically cleared
by the completion of the PCI write.
the MSI enabled HCs don't need to clear interrupt pending bit, but
hcd->irq = 0 doesn't equal to MSI enabled HCD. At some Dual-role
controller software designs, it sets hcd->irq as 0 to avoid HCD
requesting interrupt, and they want to decide when to call usb_hcd_irq
by software.
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc')
0 files changed, 0 insertions, 0 deletions