Hi Aleandre, > -----Original Message----- > From: Alexandre Belloni [mailto:alexandre.belloni@xxxxxxxxxxxxxxxxxx] > Sent: 2016年6月17日 21:55 > To: Yang, Wenyou <Wenyou.Yang@xxxxxxxxx> > Cc: Rob Herring <robh@xxxxxxxxxx>; Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>; > Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; Ferre, Nicolas > <Nicolas.FERRE@xxxxxxxxx>; Pawel Moll <pawel.moll@xxxxxxx>; Mark Brown > <broonie@xxxxxxxxxx>; Ian Campbell <ijc+devicetree@xxxxxxxxxxxxxx>; Kumar > Gala <galak@xxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux- > usb@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v3 1/2] usb: ohci-at91: Forcibly suspend ports while USB > suspend > > On 17/06/2016 at 13:44:22 +0000, Yang, Wenyou wrote : > > Hi Alexandre, > > > > > -----Original Message----- > > > From: Alexandre Belloni > > > [mailto:alexandre.belloni@xxxxxxxxxxxxxxxxxx] > > > Sent: 2016年6月9日 4:38 > > > To: Rob Herring <robh@xxxxxxxxxx> > > > Cc: Yang, Wenyou <Wenyou.Yang@xxxxxxxxx>; Alan Stern > > > <stern@xxxxxxxxxxxxxxxxxxx>; Greg Kroah-Hartman > > > <gregkh@xxxxxxxxxxxxxxxxxxx>; Ferre, Nicolas > > > <Nicolas.FERRE@xxxxxxxxx>; Pawel Moll <pawel.moll@xxxxxxx>; Mark > > > Brown <broonie@xxxxxxxxxx>; Ian Campbell > > > <ijc+devicetree@xxxxxxxxxxxxxx>; Kumar Gala <galak@xxxxxxxxxxxxxx>; > > > linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-arm- > > > kernel@xxxxxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx > > > Subject: Re: [PATCH v3 1/2] usb: ohci-at91: Forcibly suspend ports > > > while USB suspend > > > > > > On 08/06/2016 at 15:26:51 -0500, Rob Herring wrote : > > > > On Wed, Jun 08, 2016 at 12:15:10PM +0800, Wenyou Yang wrote: > > > > > In order to the save power consumption, as a workaround, suspend > > > > > forcibly the USB PORTA/B/C via set the SUSPEND_A/B/C bits of > > > > > OHCI Interrupt Configuration Register in the SFRs while OHCI USB > suspend. > > > > > > > > > > This suspend operation must be done before the USB clock is > > > > > disabled, resume after the USB clock is enabled. > > > > > > > > > > Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx> > > > > > --- > > > > > > > > > > Changes in v3: > > > > > - Change the compatible description for more precise. > > > > > > > > > > Changes in v2: > > > > > - Add compatible to support forcibly suspend the ports. > > > > > - Add soc/at91/at91_sfr.h to accommodate the defines. > > > > > - Add error checking for .sfr_regmap. > > > > > - Remove unnecessary regmap_read() statement. > > > > > > > > > > .../devicetree/bindings/usb/atmel-usb.txt | 6 +- > > > > > drivers/usb/host/ohci-at91.c | 80 > +++++++++++++++++++++- > > > > > include/soc/at91/at91_sfr.h | 29 ++++++++ > > > > > 3 files changed, 112 insertions(+), 3 deletions(-) create mode > > > > > 100644 include/soc/at91/at91_sfr.h > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/usb/atmel-usb.txt > > > > > b/Documentation/devicetree/bindings/usb/atmel-usb.txt > > > > > index 5883b73..888deaa 100644 > > > > > --- a/Documentation/devicetree/bindings/usb/atmel-usb.txt > > > > > +++ b/Documentation/devicetree/bindings/usb/atmel-usb.txt > > > > > @@ -3,8 +3,10 @@ Atmel SOC USB controllers OHCI > > > > > > > > > > Required properties: > > > > > - - compatible: Should be "atmel,at91rm9200-ohci" for USB controllers > > > > > - used in host mode. > > > > > + - compatible: Should be one of the following > > > > > + "atmel,at91rm9200-ohci" for USB controllers used in host > mode. > > > > > + "atmel,sama5d2-ohci" for USB controllers used in host mode > > > > > + on SAMA5D2 which can force to suspend. > > > > > > > > Guess I wasn't clear enough before. Drop "which can force to suspend". > > > > > > > > > > Well, my point is that we don't need a new compatible anyway. > > > > Could you give some advice?. > > > > Sure, what I mean is that you can try to get the regmap for the SFR in every case. > Depending on whether you were able to get it, you can decide to call > ohci_at91_port_suspend/resume or not (just test for sfr_regmap != NULL). I don't think so. The SFR includes a lot of miscellaneous functions, more than this one. > > -- > Alexandre Belloni, Free Electrons > Embedded Linux, Kernel and Android engineering http://free-electrons.com Best Regards, Wenyou Yang ��.n��������+%������w��{.n����z�{��ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f