Commit c1d5fb01 authored by Matwey V. Kornilov's avatar Matwey V. Kornilov Committed by Mauro Carvalho Chehab
Browse files

media: usb: pwc: Introduce TRACE_EVENTs for pwc_isoc_handler() 

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: default avatarMatwey V. Kornilov <matwey@sai.msu.ru>
Reviewed-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
parent 1e0d0a5f

drivers/media/usb/pwc/pwc-if.c

+7 −0
Original line number Diff line number Diff line
@@ -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);

include/trace/events/pwc.h

0 → 100644
+65 −0
Original line number Diff line number Diff line 
/* 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(struct pwc_frame_buf*, fbuf)

		__field(int, urb__status)

		__field(u32, urb__actual_length)

		__field(int, fbuf__filled)

		__string(name, pdev->v4l2_dev.name)

	),

	TP_fast_assign(

		__entry->urb = urb;

		__entry->fbuf = pdev->fill_buf;

		__entry->urb__status = urb->status;

		__entry->urb__actual_length = urb->actual_length;

		__entry->fbuf__filled = (pdev->fill_buf

					 ? pdev->fill_buf->filled : 0);

		__assign_str(name, pdev->v4l2_dev.name);

	),

	TP_printk("dev=%s (fbuf=%p filled=%d) urb=%p (status=%d actual_length=%u)",

		__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(struct pwc_frame_buf*, fbuf)

		__field(int, fbuf__filled)

		__string(name, pdev->v4l2_dev.name)

	),

	TP_fast_assign(

		__entry->urb = urb;

		__entry->fbuf = pdev->fill_buf;

		__entry->fbuf__filled = pdev->fill_buf->filled;

		__assign_str(name, pdev->v4l2_dev.name);

	),

	TP_printk(" dev=%s (fbuf=%p filled=%d) urb=%p",

		__get_str(name),

		__entry->fbuf,

		__entry->fbuf__filled,

		__entry->urb)

);



#endif /* _TRACE_PWC_H */



/* This part must be outside protection */

#include <trace/define_trace.h>