Re: [PATCH v2] drivers/usb: use READ_ONCE instead of deprecated ACCESS_ONCE

From: Greg KH
Date: Wed Nov 30 2016 - 09:23:11 EST


On Wed, Nov 30, 2016 at 05:50:54AM -0800, Davidlohr Bueso wrote:
> With the new standardized functions, we can replace all ACCESS_ONCE()
> calls across relevant drivers/usb/.
>
> ACCESS_ONCE() does not work reliably on non-scalar types. For example
> gcc 4.6 and 4.7 might remove the volatile tag for such accesses during
> the SRA (scalar replacement of aggregates) step:
>
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145
>
> Update the new calls regardless of if it is a scalar type, this is
> cleaner than having three alternatives.
>
> Signed-off-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
> ---
> drivers/usb/class/cdc-wdm.c | 2 +-
> drivers/usb/core/devio.c | 2 +-
> drivers/usb/core/sysfs.c | 4 ++--
> drivers/usb/gadget/udc/gr_udc.c | 4 ++--
> drivers/usb/host/ohci-hcd.c | 2 +-
> drivers/usb/host/uhci-hcd.h | 4 ++--
> 6 files changed, 9 insertions(+), 9 deletions(-)

Same comment on your driver base patch, what changed from v1?