* [PATCH 1/2] usbip: fix off-by-one frame number calculation @ 2017-11-07 10:39 ` Arnd Bergmann 2017-11-07 10:39 ` [PATCH 2/2] usbip: use monotonic timestamps Arnd Bergmann 2017-11-07 11:21 ` [PATCH 1/2] usbip: fix off-by-one frame number calculation Krzysztof Opasiak 0 siblings, 2 replies; 6+ messages in thread From: Arnd Bergmann @ 2017-11-07 10:39 UTC (permalink / raw) To: Valentina Manea, Shuah Khan, Greg Kroah-Hartman Cc: Arnd Bergmann, Krzysztof Opasiak, Johan Hovold, linux-usb, linux-kernel vgadget_get_frame returns a frame number from 0 to 2046, which may require an expensive division operation to wrap at one lower than the usual number. I can't see any reason for this, and all other drivers wrap at a power-of-two number. My best explanation is that it was a simple typo, so I'm changing the % modulo operator into a cheaper bitmask that the other drivers use, to make it wrap after 0x7ff rather than before it. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/usb/usbip/vudc_dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/usbip/vudc_dev.c b/drivers/usb/usbip/vudc_dev.c index 0c07348820ea..16fb4f85a6f6 100644 --- a/drivers/usb/usbip/vudc_dev.c +++ b/drivers/usb/usbip/vudc_dev.c @@ -145,7 +145,7 @@ static int vgadget_get_frame(struct usb_gadget *_gadget) do_gettimeofday(&now); return ((now.tv_sec - udc->start_time.tv_sec) * 1000 + (now.tv_usec - udc->start_time.tv_usec) / 1000) - % 0x7FF; + & 0x7FF; } static int vgadget_set_selfpowered(struct usb_gadget *_gadget, int value) -- 2.9.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] usbip: use monotonic timestamps 2017-11-07 10:39 ` [PATCH 1/2] usbip: fix off-by-one frame number calculation Arnd Bergmann @ 2017-11-07 10:39 ` Arnd Bergmann 2017-11-07 11:22 ` Krzysztof Opasiak 2017-11-07 11:21 ` [PATCH 1/2] usbip: fix off-by-one frame number calculation Krzysztof Opasiak 1 sibling, 1 reply; 6+ messages in thread From: Arnd Bergmann @ 2017-11-07 10:39 UTC (permalink / raw) To: Valentina Manea, Shuah Khan, Greg Kroah-Hartman Cc: Arnd Bergmann, Johan Hovold, Felipe Balbi, Krzysztof Opasiak, linux-usb, linux-kernel This gets rid of the deprecated do_gettimeofday() function in usbip. The comment above vgadget_get_frame() mentions that it suffers from issues with the time jumps due to suspend and settimeofday, so I'm changing it to use ktime_get_ts64() to use monotonic times that don't have this problem. I couldn't tell whether we should use CLOCK_MONOTONIC or CLOCK_MONOTONIC_RAW here, the difference being the exact rate when correcting for NTP. I picked monotonic time since it doesn't change the speed to the existing code and should be better synchronized with other machines we talk to. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/usb/usbip/vudc.h | 2 +- drivers/usb/usbip/vudc_dev.c | 7 +++---- drivers/usb/usbip/vudc_sysfs.c | 2 +- 3 files changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/usb/usbip/vudc.h b/drivers/usb/usbip/vudc.h index 44fb24193acd..8282362176d5 100644 --- a/drivers/usb/usbip/vudc.h +++ b/drivers/usb/usbip/vudc.h @@ -105,7 +105,7 @@ struct vudc { struct usbip_device ud; struct transfer_timer tr_timer; - struct timeval start_time; + struct timespec64 start_time; struct list_head urb_queue; diff --git a/drivers/usb/usbip/vudc_dev.c b/drivers/usb/usbip/vudc_dev.c index 16fb4f85a6f6..fe07e799e481 100644 --- a/drivers/usb/usbip/vudc_dev.c +++ b/drivers/usb/usbip/vudc_dev.c @@ -136,15 +136,14 @@ struct vep *vudc_find_endpoint(struct vudc *udc, u8 address) /* gadget ops */ -/* FIXME - this will probably misbehave when suspend/resume is added */ static int vgadget_get_frame(struct usb_gadget *_gadget) { - struct timeval now; + struct timespec64 now; struct vudc *udc = usb_gadget_to_vudc(_gadget); - do_gettimeofday(&now); + ktime_get_ts64(&now); return ((now.tv_sec - udc->start_time.tv_sec) * 1000 + - (now.tv_usec - udc->start_time.tv_usec) / 1000) + (now.tv_nsec - udc->start_time.tv_nsec) / NSEC_PER_MSEC) & 0x7FF; } diff --git a/drivers/usb/usbip/vudc_sysfs.c b/drivers/usb/usbip/vudc_sysfs.c index 7d978b824ed4..49e0123caa53 100644 --- a/drivers/usb/usbip/vudc_sysfs.c +++ b/drivers/usb/usbip/vudc_sysfs.c @@ -162,7 +162,7 @@ static ssize_t store_sockfd(struct device *dev, struct device_attribute *attr, udc->ud.status = SDEV_ST_USED; spin_unlock_irq(&udc->ud.lock); - do_gettimeofday(&udc->start_time); + ktime_get_ts64(&udc->start_time); v_start_timer(udc); udc->connected = 1; } else { -- 2.9.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] usbip: use monotonic timestamps 2017-11-07 10:39 ` [PATCH 2/2] usbip: use monotonic timestamps Arnd Bergmann @ 2017-11-07 11:22 ` Krzysztof Opasiak 2017-11-07 21:10 ` Shuah Khan 0 siblings, 1 reply; 6+ messages in thread From: Krzysztof Opasiak @ 2017-11-07 11:22 UTC (permalink / raw) To: Arnd Bergmann, Valentina Manea, Shuah Khan, Greg Kroah-Hartman Cc: Johan Hovold, Felipe Balbi, linux-usb, linux-kernel On 11/07/2017 11:39 AM, Arnd Bergmann wrote: > This gets rid of the deprecated do_gettimeofday() function in usbip. > The comment above vgadget_get_frame() mentions that it suffers > from issues with the time jumps due to suspend and settimeofday, > so I'm changing it to use ktime_get_ts64() to use monotonic times > that don't have this problem. > > I couldn't tell whether we should use CLOCK_MONOTONIC or > CLOCK_MONOTONIC_RAW here, the difference being the exact rate > when correcting for NTP. I picked monotonic time since it doesn't > change the speed to the existing code and should be better > synchronized with other machines we talk to. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Looks good to me: Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com> -- Krzysztof Opasiak Samsung R&D Institute Poland Samsung Electronics ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] usbip: use monotonic timestamps 2017-11-07 11:22 ` Krzysztof Opasiak @ 2017-11-07 21:10 ` Shuah Khan 0 siblings, 0 replies; 6+ messages in thread From: Shuah Khan @ 2017-11-07 21:10 UTC (permalink / raw) To: Krzysztof Opasiak, Arnd Bergmann, Valentina Manea, Greg Kroah-Hartman Cc: Johan Hovold, Felipe Balbi, linux-usb, linux-kernel, Shuah Khan, Shuah Khan On 11/07/2017 04:22 AM, Krzysztof Opasiak wrote: > > > On 11/07/2017 11:39 AM, Arnd Bergmann wrote: >> This gets rid of the deprecated do_gettimeofday() function in usbip. >> The comment above vgadget_get_frame() mentions that it suffers >> from issues with the time jumps due to suspend and settimeofday, >> so I'm changing it to use ktime_get_ts64() to use monotonic times >> that don't have this problem. >> >> I couldn't tell whether we should use CLOCK_MONOTONIC or >> CLOCK_MONOTONIC_RAW here, the difference being the exact rate >> when correcting for NTP. I picked monotonic time since it doesn't >> change the speed to the existing code and should be better >> synchronized with other machines we talk to. >> >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > Looks good to me: > Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com> > Acked-by: Shuah Khan <shuahkh@osg.samsung.com> thanks, -- Shuah ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] usbip: fix off-by-one frame number calculation 2017-11-07 10:39 ` [PATCH 1/2] usbip: fix off-by-one frame number calculation Arnd Bergmann 2017-11-07 10:39 ` [PATCH 2/2] usbip: use monotonic timestamps Arnd Bergmann @ 2017-11-07 11:21 ` Krzysztof Opasiak 2017-11-07 21:10 ` Shuah Khan 1 sibling, 1 reply; 6+ messages in thread From: Krzysztof Opasiak @ 2017-11-07 11:21 UTC (permalink / raw) To: Arnd Bergmann, Valentina Manea, Shuah Khan, Greg Kroah-Hartman Cc: Johan Hovold, linux-usb, linux-kernel On 11/07/2017 11:39 AM, Arnd Bergmann wrote: > vgadget_get_frame returns a frame number from 0 to 2046, which > may require an expensive division operation to wrap at one lower > than the usual number. > > I can't see any reason for this, and all other drivers wrap at > a power-of-two number. My best explanation is that it was a simple > typo, so I'm changing the % modulo operator into a cheaper bitmask > that the other drivers use, to make it wrap after 0x7ff rather than > before it. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Looks good to me: Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com> -- Krzysztof Opasiak Samsung R&D Institute Poland Samsung Electronics ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] usbip: fix off-by-one frame number calculation 2017-11-07 11:21 ` [PATCH 1/2] usbip: fix off-by-one frame number calculation Krzysztof Opasiak @ 2017-11-07 21:10 ` Shuah Khan 0 siblings, 0 replies; 6+ messages in thread From: Shuah Khan @ 2017-11-07 21:10 UTC (permalink / raw) To: Krzysztof Opasiak, Arnd Bergmann, Valentina Manea, Greg Kroah-Hartman Cc: Johan Hovold, linux-usb, linux-kernel On 11/07/2017 04:21 AM, Krzysztof Opasiak wrote: > > > On 11/07/2017 11:39 AM, Arnd Bergmann wrote: >> vgadget_get_frame returns a frame number from 0 to 2046, which >> may require an expensive division operation to wrap at one lower >> than the usual number. >> >> I can't see any reason for this, and all other drivers wrap at >> a power-of-two number. My best explanation is that it was a simple >> typo, so I'm changing the % modulo operator into a cheaper bitmask >> that the other drivers use, to make it wrap after 0x7ff rather than >> before it. >> >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > Looks good to me: > Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com> > Acked-by: Shuah Khan <shuahkh@osg.samsung.com> thanks, -- Shuah ^ permalink raw reply [flat|nested] 6+ messages in thread
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2017-11-07 10:39 ` [PATCH 1/2] usbip: fix off-by-one frame number calculation Arnd Bergmann
2017-11-07 10:39 ` [PATCH 2/2] usbip: use monotonic timestamps Arnd Bergmann
2017-11-07 11:22 ` Krzysztof Opasiak
2017-11-07 21:10 ` Shuah Khan
2017-11-07 11:21 ` [PATCH 1/2] usbip: fix off-by-one frame number calculation Krzysztof Opasiak
2017-11-07 21:10 ` Shuah Khan
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