diff options
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/host/isp1760-hcd.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/usb/host/isp1760-hcd.c b/drivers/usb/host/isp1760-hcd.c index 3172c0fd2a6d..cd07ea3f0c63 100644 --- a/drivers/usb/host/isp1760-hcd.c +++ b/drivers/usb/host/isp1760-hcd.c @@ -819,6 +819,13 @@ static void enqueue_an_ATL_packet(struct usb_hcd *hcd, struct isp1760_qh *qh, u32 atl_regs, payload; u32 buffstatus; + /* + * When this function is called from the interrupt handler to enqueue + * a follow-up packet, the SKIP register gets written and read back + * almost immediately. With ISP1761, this register requires a delay of + * 195ns between a write and subsequent read (see section 15.1.1.3). + */ + ndelay(195); skip_map = isp1760_readl(hcd->regs + HC_ATL_PTD_SKIPMAP_REG); BUG_ON(!skip_map); @@ -853,6 +860,13 @@ static void enqueue_an_INT_packet(struct usb_hcd *hcd, struct isp1760_qh *qh, u32 int_regs, payload; u32 buffstatus; + /* + * When this function is called from the interrupt handler to enqueue + * a follow-up packet, the SKIP register gets written and read back + * almost immediately. With ISP1761, this register requires a delay of + * 195ns between a write and subsequent read (see section 15.1.1.3). + */ + ndelay(195); skip_map = isp1760_readl(hcd->regs + HC_INT_PTD_SKIPMAP_REG); BUG_ON(!skip_map); |