On Thu, Mar 23, 2017 at 03:39:20PM +0800, pierre kuo wrote: > hi Greg: > > 2017-03-23 15:15 GMT+08:00 Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>: > > On Thu, Mar 23, 2017 at 03:09:05PM +0800, pierre Kuo wrote: > >> for sitd_link and itd_link, put wmb after the last memory access to make > >> sure ehci->period[frame] is visible before starting period schedule > > > > Is this fixing a known issue/bug that people are hitting? Or are you > > just finding this by looking at the code? > I just finding this by looking at the code. > > > > >> > >> Signed-off-by: pierre Kuo <vichy.kuo@xxxxxxxxx> > >> --- > >> drivers/usb/host/ehci-sched.c | 6 ++++-- > >> 1 file changed, 4 insertions(+), 2 deletions(-) > >> > >> diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c > >> index 980a6b3..9bb708a 100644 > >> --- a/drivers/usb/host/ehci-sched.c > >> +++ b/drivers/usb/host/ehci-sched.c > >> @@ -1754,8 +1754,9 @@ static void reserve_release_iso_bandwidth(struct ehci_hcd *ehci, > >> itd->hw_next = *hw_p; > >> prev->itd = itd; > >> itd->frame = frame; > >> - wmb(); > >> *hw_p = cpu_to_hc32(ehci, itd->itd_dma | Q_TYPE_ITD); > >> + /* make sure ehci->period[frame] is visible */ > > > > why an extra space in the comment? > I use cvim template, and it will automatically put space at end of /* > and before */ That's fine, but why did you add another one manually? > since ./scripts/checkpatch.pl didn't complain, so I sent it out. > should I remove the space and resent again? Of course. > > And is the comment correct here? > The comment is added due to ./scripts/checkpatch.pl grumble me there > should be comment before wmb(); Is the text of the comment correct? It doesn't seem so to me... thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
