[U-Boot] [PATCH] usb: remove unnecessary packed attributes
Marek Vasut
marex at denx.de
Thu Aug 30 22:59:53 CEST 2012
Dear Marek Vasut,
> Dear Lucas Stach,
>
> > We don't actually need to pack those structs, as they
> > are not used to do actual hardware access.
> >
> > This avoids some unaligned accesses and therefore makes
> > the EHCI stack work on ARMv7 without compiler workarounds.
> >
> > Signed-off-by: Lucas Stach <dev at lynxeye.de>
>
> I need to review this properly, will get back to it soon.
My 7th sense is telling me, these descriptors are sent across the bus.
ehci_submit_root() puts them into buffer and then ehci_submit_async() blasts
them. I believe they must be packed, otherwise the format expected by devices on
the bus won't match and it'll fall apart.
> Until then, CCing other good fellows.
>
> > ---
> >
> > drivers/usb/host/ehci-hcd.c | 2 +-
> > include/usb.h | 2 +-
> > 2 Dateien geändert, 2 Zeilen hinzugefügt(+), 2 Zeilen entfernt(-)
> >
> > diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
> > index 18b4bc6..2f4fa5e 100644
> > --- a/drivers/usb/host/ehci-hcd.c
> > +++ b/drivers/usb/host/ehci-hcd.c
> > @@ -45,7 +45,7 @@ static struct descriptor {
> >
> > struct usb_linux_config_descriptor config;
> > struct usb_linux_interface_descriptor interface;
> > struct usb_endpoint_descriptor endpoint;
> >
> > -} __attribute__ ((packed)) descriptor = {
> > +} descriptor = {
> >
> > {
> >
> > 0x8, /* bDescLength */
> > 0x29, /* bDescriptorType: hub descriptor */
> >
> > diff --git a/include/usb.h b/include/usb.h
> > index ba3d169..63730ee 100644
> > --- a/include/usb.h
> > +++ b/include/usb.h
> > @@ -369,7 +369,7 @@ struct usb_hub_descriptor {
> >
> > unsigned char PortPowerCtrlMask[(USB_MAXCHILDREN+1+7)/8];
> > /* DeviceRemovable and PortPwrCtrlMask want to be variable-length
> >
> > bitmaps that hold max 255 entries. (bit0 is ignored) */
> >
> > -} __attribute__ ((packed));
> > +};
> >
> > struct usb_hub_device {
>
> Best regards,
> Marek Vasut
Best regards,
Marek Vasut
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