On 8/18/2015 2:41 AM, Yunzhi Li wrote:
> We initiate dwc2 usb controller in BIOS, dwc2_core_reset() should
> be called before dwc2_get_hwparams() to reset core registers to
> default value. Without this the FIFO setting might be incorrect
> because calculating FIFO size need power-on value of
> GRXFSIZ/GNPTXFSIZ/HPTXFSIZ registers.
>
> This patch could avoid warnning massage like in rk3288 platform:
> [ 2.074764] dwc2 ff580000.usb: 256 invalid for
> host_perio_tx_fifo_size. Check HW configuration.
>
> Signed-off-by: Yunzhi Li <lyz@xxxxxxxxxxxxxx>
>
> ---
>
> drivers/usb/dwc2/core.c | 2 +-
> drivers/usb/dwc2/core.h | 1 +
> drivers/usb/dwc2/platform.c | 6 ++++++
> 3 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
> index c3cc1a7..86d1d65 100644
> --- a/drivers/usb/dwc2/core.c
> +++ b/drivers/usb/dwc2/core.c
> @@ -474,7 +474,7 @@ static void dwc2_init_fs_ls_pclk_sel(struct dwc2_hsotg *hsotg)
> * Do core a soft reset of the core. Be careful with this because it
> * resets all the internal state machines of the core.
> */
> -static int dwc2_core_reset(struct dwc2_hsotg *hsotg)
> +int dwc2_core_reset(struct dwc2_hsotg *hsotg)
> {
> u32 greset;
> int count = 0;
> diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
> index 0ed87620..5d95aec 100644
> --- a/drivers/usb/dwc2/core.h
> +++ b/drivers/usb/dwc2/core.h
> @@ -846,6 +846,7 @@ enum dwc2_halt_status {
> * The following functions support initialization of the core driver component
> * and the DWC_otg controller
> */
> +extern int dwc2_core_reset(struct dwc2_hsotg *hsotg);
> extern void dwc2_core_host_init(struct dwc2_hsotg *hsotg);
> extern int dwc2_enter_hibernation(struct dwc2_hsotg *hsotg);
> extern int dwc2_exit_hibernation(struct dwc2_hsotg *hsotg, bool restore);
> diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
> index 9093530..8d3be4a 100644
> --- a/drivers/usb/dwc2/platform.c
> +++ b/drivers/usb/dwc2/platform.c
> @@ -243,6 +243,12 @@ static int dwc2_driver_probe(struct platform_device *dev)
> spin_lock_init(&hsotg->lock);
> mutex_init(&hsotg->init_mutex);
>
> + /*
> + * Reset before dwc2_get_hwparams() then it could get power-on real
> + * reset value form registers.
> + */
> + dwc2_core_reset(hsotg);
> +
> /* Detect config values from hardware */
> retval = dwc2_get_hwparams(hsotg);
> if (retval)
>
Hi Yunzhi,
My concern is with the delays due to calling the dwc2_core_reset
during probe. You could factor out the assertion of the core
soft reset from the dwc2_core_reset and just use that before
calling dwc2_get_hwparams().
You had previously addressed the lengthy probe time issue here:
http://marc.info/?l=linux-usb&m=142357721304377
This reducing delays patch looks reasonable to me and I think it
should get merged also. I'll do some testing with it later this
week.
John
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