>From d5f26c1595f211ea7d46fca91551f70d1207330d Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Tue, 19 Sep 2017 14:54:58 +0300 Subject: [PATCH 1/2] xhci: Add option to get next extended capability in list by passing id = 0 Modify xhci_find_next_ext_cap(base, offset, id) to return the next capability offset if 0 is passed for id. Otherwise it will behave as previously and return the offset of the next capability with matching id capability id 0 is not used by xhci (reserved) This is useful when we want to loop through all capabilities. Signed-off-by: Mathias Nyman --- drivers/usb/host/xhci-ext-caps.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/xhci-ext-caps.h b/drivers/usb/host/xhci-ext-caps.h index 28deea5..c1b4042 100644 --- a/drivers/usb/host/xhci-ext-caps.h +++ b/drivers/usb/host/xhci-ext-caps.h @@ -96,7 +96,8 @@ * @base PCI MMIO registers base address. * @start address at which to start looking, (0 or HCC_PARAMS to start at * beginning of list) - * @id Extended capability ID to search for. + * @id Extended capability ID to search for, or 0 for the next + * capability * * Returns the offset of the next matching extended capability structure. * Some capabilities can occur several times, e.g., the XHCI_EXT_CAPS_PROTOCOL, @@ -122,7 +123,7 @@ static inline int xhci_find_next_ext_cap(void __iomem *base, u32 start, int id) val = readl(base + offset); if (val == ~0) return 0; - if (XHCI_EXT_CAPS_ID(val) == id && offset != start) + if (offset != start && (id == 0 || XHCI_EXT_CAPS_ID(val) == id)) return offset; next = XHCI_EXT_CAPS_NEXT(val); -- 1.9.1