From b375e1169d8ecc9e9db3ecba8147d484b5510833 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 6 Nov 2009 12:32:23 -0500 Subject: USB: add scatter-gather support to usbmon This patch (as1301) adds support to usbmon for scatter-gather URBs. The text interface looks at only the first scatterlist element, since it never copies more than 32 bytes of data anyway. The binary interface copies as much data as possible up to the first non-addressable buffer. Signed-off-by: Alan Stern CC: Pete Zaitcev Signed-off-by: Greg Kroah-Hartman --- drivers/usb/mon/mon_text.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) (limited to 'drivers/usb/mon/mon_text.c') diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c index 9f1a9227ebe6..047568ff223d 100644 --- a/drivers/usb/mon/mon_text.c +++ b/drivers/usb/mon/mon_text.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include "usb_mon.h" @@ -137,6 +138,8 @@ static inline char mon_text_get_setup(struct mon_event_text *ep, static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb, int len, char ev_type, struct mon_bus *mbus) { + void *src; + if (len <= 0) return 'L'; if (len >= DATA_MAX) @@ -150,10 +153,24 @@ static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb, return '>'; } - if (urb->transfer_buffer == NULL) - return 'Z'; /* '0' would be not as pretty. */ + if (urb->num_sgs == 0) { + src = urb->transfer_buffer; + if (src == NULL) + return 'Z'; /* '0' would be not as pretty. */ + } else { + struct scatterlist *sg = urb->sg->sg; + + /* If IOMMU coalescing occurred, we cannot trust sg_page */ + if (urb->sg->nents != urb->num_sgs || + PageHighMem(sg_page(sg))) + return 'D'; + + /* For the text interface we copy only the first sg buffer */ + len = min_t(int, sg->length, len); + src = sg_virt(sg); + } - memcpy(ep->data, urb->transfer_buffer, len); + memcpy(ep->data, src, len); return 0; } -- cgit v1.2.1