On Thu, 9 Aug 2018 12:33:06 +0300 "Matwey V. Kornilov" <matwey@xxxxxxxxxx> wrote: > There were reports that PWC-based webcams don't work at some > embedded ARM platforms. [1] Isochronous transfer handler seems to > work too long leading to the issues in MUSB USB host subsystem. > Also note, that urb->giveback() handlers are still called with > disabled interrupts. In order to be able to measure performance of > PWC driver, traces are introduced in URB handler section. > > [1] https://www.spinics.net/lists/linux-usb/msg165735.html > > Signed-off-by: Matwey V. Kornilov <matwey@xxxxxxxxxx> > --- > drivers/media/usb/pwc/pwc-if.c | 7 +++++ > include/trace/events/pwc.h | 64 ++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 71 insertions(+) > create mode 100644 include/trace/events/pwc.h > > diff --git a/drivers/media/usb/pwc/pwc-if.c b/drivers/media/usb/pwc/pwc-if.c > index 54b036d39c5b..72d2897a4b9f 100644 > --- a/drivers/media/usb/pwc/pwc-if.c > +++ b/drivers/media/usb/pwc/pwc-if.c > @@ -76,6 +76,9 @@ > #include "pwc-dec23.h" > #include "pwc-dec1.h" > > +#define CREATE_TRACE_POINTS > +#include <trace/events/pwc.h> > + > /* Function prototypes and driver templates */ > > /* hotplug device table support */ > @@ -260,6 +263,8 @@ static void pwc_isoc_handler(struct urb *urb) > int i, fst, flen; > unsigned char *iso_buf = NULL; > > + trace_pwc_handler_enter(urb, pdev); > + > if (urb->status == -ENOENT || urb->status == -ECONNRESET || > urb->status == -ESHUTDOWN) { > PWC_DEBUG_OPEN("URB (%p) unlinked %ssynchronously.\n", > @@ -348,6 +353,8 @@ static void pwc_isoc_handler(struct urb *urb) > } > > handler_end: > + trace_pwc_handler_exit(urb, pdev); > + > i = usb_submit_urb(urb, GFP_ATOMIC); > if (i != 0) > PWC_ERROR("Error (%d) re-submitting urb in pwc_isoc_handler.\n", i); > diff --git a/include/trace/events/pwc.h b/include/trace/events/pwc.h > new file mode 100644 > index 000000000000..71ba98770537 > --- /dev/null > +++ b/include/trace/events/pwc.h > @@ -0,0 +1,64 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#if !defined(_TRACE_PWC_H) || defined(TRACE_HEADER_MULTI_READ) > +#define _TRACE_PWC_H > + > +#include <linux/usb.h> > +#include <linux/tracepoint.h> > + > +#undef TRACE_SYSTEM > +#define TRACE_SYSTEM pwc > + > +TRACE_EVENT(pwc_handler_enter, > + TP_PROTO(struct urb *urb, struct pwc_device *pdev), > + TP_ARGS(urb, pdev), > + TP_STRUCT__entry( > + __field(struct urb*, urb) > + __field(int, urb__status) > + __field(u32, urb__actual_length) > + __field(const char*, name) name needs to be a __string. Never save pointers that you will dereference in the print_fmt, as you never know if those pointers will exist later. Not to mention, userspace tools like trace-cmd and perf have no idea how to display them. You want: __string( name, pdev->v4l2_dev.name ), > + __field(struct pwc_frame_buf*, fbuf) > + __field(int, fbuf__filled) > + ), > + TP_fast_assign( > + __entry->urb = urb; > + __entry->urb__status = urb->status; > + __entry->urb__actual_length = urb->actual_length; > + __entry->name = pdev->v4l2_dev.name; And here you assign it with: __assign_str(name, pdev->v4l2_dev.name); > + __entry->fbuf = pdev->fill_buf; > + __entry->fbuf__filled = (pdev->fill_buf ? pdev->fill_buf->filled : 0); > + ), > + TP_printk("dev=%s (fbuf=%p filled=%d) urb=%p (status=%d actual_length=%u)", > + __entry->name, And display it with: __get_str(name), > + __entry->fbuf, > + __entry->fbuf__filled, > + __entry->urb, > + __entry->urb__status, > + __entry->urb__actual_length) > +); > + > +TRACE_EVENT(pwc_handler_exit, > + TP_PROTO(struct urb *urb, struct pwc_device* pdev), > + TP_ARGS(urb, pdev), > + TP_STRUCT__entry( > + __field(struct urb*, urb) > + __field(const char*, name) > + __field(struct pwc_frame_buf*, fbuf) > + __field(int, fbuf__filled) > + ), > + TP_fast_assign( > + __entry->urb = urb; > + __entry->name = pdev->v4l2_dev.name; > + __entry->fbuf = pdev->fill_buf; > + __entry->fbuf__filled = pdev->fill_buf->filled; > + ), > + TP_printk(" dev=%s (fbuf=%p filled=%d) urb=%p", > + __entry->name, Same thing here. -- Steve > + __entry->fbuf, > + __entry->fbuf__filled, > + __entry->urb) > +); > + > +#endif /* _TRACE_PWC_H */ > + > +/* This part must be outside protection */ > +#include <trace/define_trace.h>
