On Wed, May 14, 2014 at 12:13:08PM +0530, Pratyush Anand wrote:
> Hi Paul/Felip,
>
> On Wed, May 07, 2014 at 11:15:33AM +0530, Pratyush Anand wrote:
> > Hi Paul,
> >
> > On Tue, May 06, 2014 at 11:54:19AM +0800, Pratyush ANAND wrote:
> > > All dwc3 based xhci host controller supports USB3.0 LPM functionality.
> > > Therefore enable it in platform data for all dwc3 based xhci device.
> > >
> > > Signed-off-by: Pratyush Anand <pratyush.anand@xxxxxx>
> > > ---
> > > drivers/usb/dwc3/host.c | 12 ++++++++++++
> > > 1 file changed, 12 insertions(+)
> > >
> > > diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> > > index 32db328..1fda6e8 100644
> > > --- a/drivers/usb/dwc3/host.c
> > > +++ b/drivers/usb/dwc3/host.c
> > > @@ -16,12 +16,14 @@
> > > */
> > >
> > > #include <linux/platform_device.h>
> > > +#include <linux/usb/xhci_pdriver.h>
> > >
> > > #include "core.h"
> > >
> > > int dwc3_host_init(struct dwc3 *dwc)
> > > {
> > > struct platform_device *xhci;
> > > + struct usb_xhci_pdata pdata;
> > > int ret;
> > >
> > > xhci = platform_device_alloc("xhci-hcd", PLATFORM_DEVID_AUTO);
> > > @@ -46,6 +48,16 @@ int dwc3_host_init(struct dwc3 *dwc)
> > > goto err1;
> > > }
> > >
> > > + memset(&pdata, 0, sizeof(pdata));
> > > +
> > > + pdata.usb3_lpm_capable = 1;
> >
> > Even though all dwc3 platform is usb3 lpm capable, I would like to
> > make it optional, as I see some performance impact when capability is
> > enabled vs not enabled.
> >
> > When enabled:
> > ./testusb -a -t 2 -c 1000000 -s 1024
> > takes 198 sec to execute
> > vs when not enabled , it takes 169 sec to execute.
> >
> > And this impact is with a gadget with maxburst and mult as 0.
> > Performance will be impacted more with higher maxburst and mult.
> >
> > So making it optional would be a better choice. What do you say.
>
> Do you think that it would be wiser to add an optional flag in
> usb3-lpm-enable in dwc3 dt? If yes, I will send a quick next revision,
> else I think patches can be applied.
in that case, let's wrap with a Kconfig boolean symbol. It's not worth
to add DT for this, it's either enabled for all instances, or for none.
cheers
--
balbi
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