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authorMatwey V. Kornilov <matwey@sai.msu.ru>2018-11-09 20:03:26 +0100
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-01-16 17:15:11 +0100
commitc1d5fb019f65e1093c77734356f97b6e7ac4d629 (patch)
tree547851420ab5c4a9d254417f0661336139adae13 /drivers/media/usb
parentmedia: s5p-mfc: fix incorrect bus assignment in virtual child device (diff)
downloadlinux-c1d5fb019f65e1093c77734356f97b6e7ac4d629.tar.xz
linux-c1d5fb019f65e1093c77734356f97b6e7ac4d629.zip
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: Matwey V. Kornilov <matwey@sai.msu.ru> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'drivers/media/usb')
-rw-r--r--drivers/media/usb/pwc/pwc-if.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/media/usb/pwc/pwc-if.c b/drivers/media/usb/pwc/pwc-if.c
index 72704f4d5330..53c111bd5a22 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);