Re: [PATCH 13/18] usb: dwc2: Move reset into dwc2_get_hwparams()

[Doug Anderson]

John,

On Wed, Dec 2, 2015 at 11:14 AM, John Youn  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 
> ---
>  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.


> @@ -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...

-Doug
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Re: [PATCH 13/18] usb: dwc2: Move reset into dwc2_get_hwparams()

[John Youn]

On 12/9/2015 4:46 PM, Doug Anderson wrote:
> John,
> 
> On Wed, Dec 2, 2015 at 11:14 AM, John Youn  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 
>> ---
>>  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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[PATCH 13/18] usb: dwc2: Move reset into dwc2_get_hwparams()

[John Youn]

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 
---
 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.
@@ -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);
+
if (hsotg->dr_mode != USB_DR_MODE_HOST) {
retval = dwc2_gadget_init(hsotg, irq);
if (retval)
-- 
2.6.3

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