[v9,07/12] xhci: Add option to get next extended capability in list by passing id = 0
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Date: 2018-03-20 12:57:08
Also in:
lkml, platform-driver-x86
Subsystem:
the rest, usb subsystem, usb xhci driver · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Mathias Nyman
From: Mathias Nyman <redacted> 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 <redacted> Reviewed-by: Andy Shevchenko <redacted> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> --- Changes in v4: -Add Andy's Reviewed-by Changes in v2: -Added Heikki's Reviewed-by --- 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 bf7316e130d3..631e7cc62604 100644
--- a/drivers/usb/host/xhci-ext-caps.h
+++ b/drivers/usb/host/xhci-ext-caps.h@@ -84,7 +84,8 @@ * @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,
@@ -110,7 +111,7 @@ 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);