[U-Boot] [PATCH 5/8] tegra: usb: move controller init into start_port

Simon Glass
2012-10-30T13:48:02Z

Hi Lucas,

On Tue, Oct 30, 2012 at 6:37 AM, Lucas Stach <dev@lynxeye.de> wrote:
> Am Dienstag, den 30.10.2012, 06:27 -0700 schrieb Simon Glass:
>> Hi Lucas,
>>
>> On Tue, Oct 30, 2012 at 2:22 AM, Lucas Stach <dev@lynxeye.de> wrote:
>> > There is no need to init a USB controller before the upper layers indicate
>> > that they are actually going to use it.
>> >
>> > board_usb_init now only parses the device tree and sets up the common pll.
>> >
>> > Signed-off-by: Lucas Stach <dev@lynxeye.de>
>> > ---
>> > arch/arm/cpu/armv7/tegra20/usb.c | 47 +++++++++++++++-------------------------
>> > 1 Datei ge?ndert, 18 Zeilen hinzugef?gt(+), 29 Zeilen entfernt(-)
>> >
>> > diff --git a/arch/arm/cpu/armv7/tegra20/usb.c b/arch/arm/cpu/armv7/tegra20/usb.c
>> > index cf800b1..e372b8b 100644
>> > --- a/arch/arm/cpu/armv7/tegra20/usb.c
>> > +++ b/arch/arm/cpu/armv7/tegra20/usb.c
>> > @@ -417,44 +417,29 @@ static int init_ulpi_usb_controller(struct fdt_usb *config)
>> > }
>> > #endif
>> >
>> > -/**
>> > - * Add a new USB port to the list of available ports.
>> > - *
>> > - * @param config USB port configuration
>> > - * @return 0 if ok, -1 if error (too many ports)
>> > - */
>> > -static int add_port(struct fdt_usb *config)
>> > +int tegrausb_start_port(int portnum, u32 *hccr, u32 *hcor)
>> > {
>> > - if (port_count == USB_PORTS_MAX) {
>> > - printf("tegrausb: Cannot register more than %d ports\n",
>> > - USB_PORTS_MAX);
>> > + struct fdt_usb *config;
>> > + struct usb_ctlr *usbctlr;
>> > +
>> > + if (portnum >= port_count)
>> > return -1;
>> > - }
>> > +
>> > + config = &port[portnum];
>> >
>> > if (config->utmi && init_utmi_usb_controller(config)) {
>> > - printf("tegrausb: Cannot init port\n");
>> > + printf("tegrausb: Cannot init port %d\n", portnum);
>> > return -1;
>> > }
>> >
>> > if (config->ulpi && init_ulpi_usb_controller(config)) {
>> > - printf("tegrausb: Cannot init port\n");
>> > + printf("tegrausb: Cannot init port %d\n", portnum);
>> > return -1;
>> > }
>> >
>> > - port[port_count++] = *config;
>> > -
>> > - return 0;
>> > -}
>> > + set_host_mode(config);
>>
>> This is good, but now I think you will re-init the USB peripheral at
>> every 'usb start'. Perhaps you should remember whether it has been
>> inited and only do it the first time?
>
> I have to look this up, but the upper USB layers should not call those
> lowlevel init functions repeatedly unless explicitly asked for it
> through a "usb reset" or the like. If it actually does so it's a bug in
> the upper layer and should not be fixed up in the lowlevel functions.

Perhaps, but you have to write your code in the environment that
exists. At present usb_lowlevel_init() is called on every 'usb start'
(and ehci_hcd_init() from that).

Regards,
Simon

>
> Regards,
> Lucas
>
>