Re: [PATCH v4 2/2] Embedded USB Debugger (EUD) driver

[Dwivedi, Avaneesh Kumar (avani)]

On 2/16/2020 10:05 PM, Greg KH wrote:
> On Sun, Feb 16, 2020 at 09:52:19PM +0530, Dwivedi, Avaneesh Kumar (avani) wrote:
> > On 2/7/2020 3:34 PM, Greg KH wrote:
> > > On Fri, Jan 31, 2020 at 10:13:31AM +0530, Avaneesh Kumar Dwivedi wrote:
> > > > Add support for control peripheral of EUD (Embedded USB Debugger) to
> > > > listen to events such as USB attach/detach, charger enable/disable, pet
> > > > EUD to indicate software is functional. Reusing the platform device kobj,
> > > > sysfs entry 'enable' is created to enable or disable EUD.
> > > >
> > > > Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@xxxxxxxxxxxxxx>
> > > > Signed-off-by: Prakruthi Deepak Heragu <pheragu@xxxxxxxxxxxxxx>
> > > > Signed-off-by: Avaneesh Kumar Dwivedi <akdwived@xxxxxxxxxxxxxx>
> > > > ---
> > > >    Documentation/ABI/stable/sysfs-driver-msm-eud |   5 +
> > > >    drivers/soc/qcom/Kconfig                      |  12 +
> > > >    drivers/soc/qcom/Makefile                     |   1 +
> > > >    drivers/soc/qcom/eud.c                        | 329 ++++++++++++++++++++++++++
> > > >    4 files changed, 347 insertions(+)
> > > >    create mode 100644 Documentation/ABI/stable/sysfs-driver-msm-eud
> > > >    create mode 100644 drivers/soc/qcom/eud.c
> > > >
> > > > diff --git a/Documentation/ABI/stable/sysfs-driver-msm-eud b/Documentation/ABI/stable/sysfs-driver-msm-eud
> > > > new file mode 100644
> > > > index 0000000..d96ae05
> > > > --- /dev/null
> > > > +++ b/Documentation/ABI/stable/sysfs-driver-msm-eud
> > > > @@ -0,0 +1,5 @@
> > > > +What:           /sys/bus/platform/drivers/msm-eud/enable
> > > > +Date:           Jan 2020
> > > > +Contact:        Avaneesh Kumar Dwivedi <akdwived@xxxxxxxxxxxxxx>
> > > > +Description:    Enable/Disable use of eud device.
> > > What are valid values to be used here?
> > it should be bool variable relying on 0 or 1.
> Then document it.
OK
> > > > +Users:          User space debug application which intend to use EUD h/w block.
> > > > diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> > > > index d0a73e7..6b7c9d0 100644
> > > > --- a/drivers/soc/qcom/Kconfig
> > > > +++ b/drivers/soc/qcom/Kconfig
> > > > @@ -202,4 +202,16 @@ config QCOM_APR
> > > >    	  application processor and QDSP6. APR is
> > > >    	  used by audio driver to configure QDSP6
> > > >    	  ASM, ADM and AFE modules.
> > > > +
> > > > +config QCOM_EUD
> > > > +       tristate "QTI Embedded USB Debugger (EUD)"
> > > > +       depends on ARCH_QCOM
> > > Why not let everyone test build this?
> > EUD is Qualcomm IP, shall not it be associated with ARCH_QCOM?
> No, why can't everyone buid it for testing?  What about when I want to
> build a generic arm64 kernel to run on multiple SoCs?
>
> Do not put dependancies in here that you really do not have.  There's no
> reason for this to be limited to that one chip, right?  And if you allow
> others to build the code, you will get proper bug reports when things
> break, and others will fix them, which is what you want.
>
> I think the ARCH_RANDOM_SOC_NAME is totally broken and needs to be, at
> most, just an arch-specific thing, if even that.
>
> Look at almost all other kernel drivers, they do not have those types of
> dependancies.
Will check and address concerns.
> > > > +	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
> > > > +	if (!chip)
> > > > +		return -ENOMEM;
> > > > +
> > > > +	chip->dev = &pdev->dev;
> > > No reference counting???
> > you mean get/put_device?
> yes.
>
> thanks,
>
> greg k-h
Thank you very much Greg for your time to review.

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