diff options
Diffstat (limited to 'drivers/usb/mon/mon_text.c')
| -rw-r--r-- | drivers/usb/mon/mon_text.c | 23 |
1 files changed, 20 insertions, 3 deletions
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 <linux/time.h> #include <linux/mutex.h> #include <linux/debugfs.h> +#include <linux/scatterlist.h> #include <asm/uaccess.h> #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; } |