On 12/9/2015 4:46 PM, Doug Anderson wrote:
> John,
>
> On Wed, Dec 2, 2015 at 11:14 AM, John Youn <John.Youn@xxxxxxxxxxxx> wrote:
>> The reset is required to get reset values of the hardware parameters but
>> the force mode is not. Move the base reset into dwc2_get_hwparams() and
>> do the reset and force mode afterwards.
>>
>> Signed-off-by: John Youn <johnyoun@xxxxxxxxxxxx>
>> ---
>> drivers/usb/dwc2/core.c | 5 +++++
>> drivers/usb/dwc2/platform.c | 8 ++------
>> 2 files changed, 7 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
>> index 382f563..7090050 100644
>> --- a/drivers/usb/dwc2/core.c
>> +++ b/drivers/usb/dwc2/core.c
>> @@ -3116,6 +3116,7 @@ int dwc2_get_hwparams(struct dwc2_hsotg *hsotg)
>> u32 hwcfg1, hwcfg2, hwcfg3, hwcfg4;
>> u32 hptxfsiz, grxfsiz, gnptxfsiz;
>> u32 gusbcfg = 0;
>> + int retval;
>>
>> /*
>> * Attempt to ensure this device is really a DWC_otg Controller.
>
> nit: technically the comment from commit aa63719d0b31 ("usb: dwc2:
> Improve handling of host and device hwparams") adding that this
> function now does a reset should have been added in this patch.
Ahh thanks. I'll fix it if I have to respin this series.
>
>
>> @@ -3135,6 +3136,10 @@ int dwc2_get_hwparams(struct dwc2_hsotg *hsotg)
>> hw->snpsid >> 12 & 0xf, hw->snpsid >> 8 & 0xf,
>> hw->snpsid >> 4 & 0xf, hw->snpsid & 0xf, hw->snpsid);
>>
>> + retval = dwc2_core_reset(hsotg);
>> + if (retval)
>> + return retval;
>> +
>> hwcfg1 = dwc2_readl(hsotg->regs + GHWCFG1);
>> hwcfg2 = dwc2_readl(hsotg->regs + GHWCFG2);
>> hwcfg3 = dwc2_readl(hsotg->regs + GHWCFG3);
>> diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
>> index f18d50f..12826a1 100644
>> --- a/drivers/usb/dwc2/platform.c
>> +++ b/drivers/usb/dwc2/platform.c
>> @@ -510,12 +510,6 @@ static int dwc2_driver_probe(struct platform_device *dev)
>> if (retval)
>> return retval;
>>
>> - /*
>> - * Reset before dwc2_get_hwparams() then it could get power-on real
>> - * reset value form registers.
>> - */
>> - dwc2_core_reset_and_force_mode(hsotg);
>> -
>> /* Detect config values from hardware */
>> retval = dwc2_get_hwparams(hsotg);
>> if (retval)
>> @@ -524,6 +518,8 @@ static int dwc2_driver_probe(struct platform_device *dev)
>> /* Validate parameter values */
>> dwc2_set_parameters(hsotg, params);
>>
>> + dwc2_core_reset_and_force_mode(hsotg);
>> +
>
> Isn't this introducing a 2nd reset that's not necessary? You already
> know that dwc2_get_hwparams() did a reset and now you're doing a 2nd
> reset. Maybe I'm misunderstanding...
I wanted to preserve setting force mode just before calling the
gadget/hcd init. Only a plain (fast) reset is required to read the HW
params.
But it is redundant. I can split out the force mode to avoid the extra
reset.
I'll send an add-on patch to this series that does that.
Regards,
John
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