Subject: [Patch v9 2/3] usb: dwc3: Add Qualcomm DWC3 glue layer driver

From: [email-masked] (Pramod Gurav)
Date: Sat, 13 Sep 2014 01:55:50 +0530

Hi Felipe,

On 13-09-2014 01:50 AM, Felipe Balbi wrote:
> On Sat, Sep 13, 2014 at 01:44:25AM +0530, Pramod Gurav wrote:
>> Andy,
>> Couple of minor comments.
>>
>> On Sat, Sep 13, 2014 at 12:58 AM, Andy Gross <[email-masked]> wrote:
>>
>>> From: "Ivan T. Ivanov" <[email-masked]>
>>>
>>> DWC3 glue layer is hardware layer around Synopsys DesignWare
>>> USB3 core. Its purpose is to supply Synopsys IP with required
>>> clocks, voltages and interface it with the rest of the SoC.
>>>
>>> Signed-off-by: Ivan T. Ivanov <[email-masked]>
>>> Signed-off-by: Andy Gross <[email-masked]>
>>> ---
>>>  drivers/usb/dwc3/Kconfig     |    8 +++
>>>  drivers/usb/dwc3/Makefile    |    1 +
>>>  drivers/usb/dwc3/dwc3-qcom.c |  131
>>> ++++++++++++++++++++++++++++++++++++++++++
>>>  3 files changed, 140 insertions(+)
>>>  create mode 100644 drivers/usb/dwc3/dwc3-qcom.c
>>>
>>>
>> <..>
>>
>>
>>> +#include <linux/platform_device.h>
>>> +
>>> +struct dwc3_qcom {
>>> +       struct device           *dev;
>>> +
>>>
>> Extra new line here.
> 
> that's not an issue however.
> 
>>> +       struct clk              *core_clk;
>>> +       struct clk              *iface_clk;
>>> +       struct clk              *sleep_clk;
>>> +};
>>> +
>>> +static int dwc3_qcom_probe(struct platform_device *pdev)
>>> +{
>>> +       struct device_node *node = pdev->dev.of_node;
>>> +       struct dwc3_qcom *qdwc;
>>> +       int ret = 0;
>>>
>> Initialization not required.
> 
> I'll fix this one as I'm already applying this patch.
> 
>>> +
>>> +       qdwc = devm_kzalloc(&pdev->dev, sizeof(*qdwc), GFP_KERNEL);
>>> +       if (!qdwc)
>>> +               return -ENOMEM;
>>> +
>>> +       platform_set_drvdata(pdev, qdwc);
>>> +
>>> +       qdwc->dev = &pdev->dev;
>>> +
>>> +       qdwc->core_clk = devm_clk_get(qdwc->dev, "core");
>>> +       if (IS_ERR(qdwc->core_clk)) {
>>> +               dev_err(qdwc->dev, "failed to get core clock\n");
>>> +               return PTR_ERR(qdwc->core_clk);
>>> +       }
>>> +
>>> +       qdwc->iface_clk = devm_clk_get(qdwc->dev, "iface");
>>> +       if (IS_ERR(qdwc->iface_clk)) {
>>> +               dev_dbg(qdwc->dev, "failed to get optional iface clock\n");
>>> +               qdwc->iface_clk = NULL;
>>> +       }
>>> +
>>> +       qdwc->sleep_clk = devm_clk_get(qdwc->dev, "sleep");
>>> +       if (IS_ERR(qdwc->sleep_clk)) {
>>> +               dev_dbg(qdwc->dev, "failed to get optional sleep clock\n");
>>> +               qdwc->sleep_clk = NULL;
>>> +       }
>>> +
>>> +       ret = clk_prepare_enable(qdwc->core_clk);
>>> +       if (ret) {
>>> +               dev_err(qdwc->dev, "failed to enable core clock\n");
>>> +               goto err_core;
>>> +       }
>>> +
>>> +       ret = clk_prepare_enable(qdwc->iface_clk);
>>>
>> Should not we check if  qdwc->iface_clk is valid?
> 
> read the sources luke.
Now I read that its initialized to NULL in fail case but should we call
prepare_enable at all if its NULL?
> 
>>> +err_clks:
>>> +       clk_disable_unprepare(qdwc->sleep_clk);
>>>
>> IS_ERR check before above statement not needed as we have continued with
>> probe even after failure og devm_clk_get?
> 
> read more carefully, there's a detail which you're missing.
>