usbmon: don't call mon_dmapeek if DMA isn't being used

This patch (as755b) fixes a bug in usbmon.  Rather than assuming all
USB host controllers use DMA, the code will check the usb_bus data
structure.  If DMA isn't used, we don't want to try peeking into a
non-existent DMA buffer!

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/mon/mon_main.c b/drivers/usb/mon/mon_main.c
index e0ed36cdfd8bcebd35be64e40db8c33e79bf4704..394bbf2f68d44f0b81807773be8a12e992fb690c 100644 (file)
--- a/drivers/usb/mon/mon_main.c
+++ b/drivers/usb/mon/mon_main.c
@@ -301,6 +301,7 @@ static void mon_bus_init(struct dentry *mondir, struct usb_bus *ubus)
         */
        mbus->u_bus = ubus;
        ubus->mon_bus = mbus;
+       mbus->uses_dma = ubus->uses_dma;
 
        rc = snprintf(name, NAMESZ, "%dt", ubus->busnum);
        if (rc <= 0 || rc >= NAMESZ)

diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c
index 775e374a960cf5de3d75c8e7803d068bb311404c..7a2346c53284b93a502b47b5911159f343a70ecc 100644 (file)
--- a/drivers/usb/mon/mon_text.c
+++ b/drivers/usb/mon/mon_text.c
@@ -75,13 +75,13 @@ static void mon_text_ctor(void *, kmem_cache_t *, unsigned long);
  */
 
 static inline char mon_text_get_setup(struct mon_event_text *ep,
-    struct urb *urb, char ev_type)
+    struct urb *urb, char ev_type, struct mon_bus *mbus)
 {
 
        if (!usb_pipecontrol(urb->pipe) || ev_type != 'S')
                return '-';
 
-       if (urb->transfer_flags & URB_NO_SETUP_DMA_MAP)
+       if (mbus->uses_dma && (urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
                return mon_dmapeek(ep->setup, urb->setup_dma, SETUP_MAX);
        if (urb->setup_packet == NULL)
                return 'Z';     /* '0' would be not as pretty. */
@@ -91,7 +91,7 @@ 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)
+    int len, char ev_type, struct mon_bus *mbus)
 {
        int pipe = urb->pipe;
 
@@ -117,7 +117,7 @@ static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb,
         * contain non-NULL garbage in case the upper level promised to
         * set DMA for the HCD.
         */
-       if (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
+       if (mbus->uses_dma && (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP))
                return mon_dmapeek(ep->data, urb->transfer_dma, len);
 
        if (urb->transfer_buffer == NULL)
@@ -161,8 +161,9 @@ static void mon_text_event(struct mon_reader_text *rp, struct urb *urb,
        /* Collecting status makes debugging sense for submits, too */
        ep->status = urb->status;
 
-       ep->setup_flag = mon_text_get_setup(ep, urb, ev_type);
-       ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type);
+       ep->setup_flag = mon_text_get_setup(ep, urb, ev_type, rp->r.m_bus);
+       ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type,
+                       rp->r.m_bus);
 
        rp->nevents++;
        list_add_tail(&ep->e_link, &rp->e_list);

diff --git a/drivers/usb/mon/usb_mon.h b/drivers/usb/mon/usb_mon.h
index 50efc8ee7c21bc6c0eb66691d7336d10bbd880be..ab9d02d5df77a448c0c829c42b5b3633fbdfc054 100644 (file)
--- a/drivers/usb/mon/usb_mon.h
+++ b/drivers/usb/mon/usb_mon.h
@@ -20,6 +20,7 @@ struct mon_bus {
        struct dentry *dent_s;          /* Debugging file */
        struct dentry *dent_t;          /* Text interface file */
        struct usb_bus *u_bus;
+       int uses_dma;
 
        /* Ref */
        int nreaders;                   /* Under mon_lock AND mbus->lock */