Re: [PATCH 3/7] drivers: soc: xilinx: add check for platform

[Michal Simek]

On 10/2/23 08:20, Greg KH wrote:
> On Mon, Oct 02, 2023 at 08:09:50AM +0200, Michal Simek wrote:
> > On 9/30/23 09:17, Greg KH wrote:
> > > On Fri, Sep 29, 2023 at 03:55:54AM -0700, Jay Buddhabhatti wrote:
> > > > Some error event IDs for Versal and Versal NET are different.
> > > > Both the platforms should access their respective error event
> > > > IDs so use sub_family_code to check for platform and check
> > > > error IDs for respective platforms. The family code is passed
> > > > via platform data to avoid platform detection again.
> > > > Platform data is setup when even driver is registered.
> > > >
> > > > Signed-off-by: Jay Buddhabhatti <jay.buddhabhatti@xxxxxxx>
> > > > ---
> > > >    drivers/firmware/xilinx/zynqmp.c        |  2 +-
> > > >    drivers/soc/xilinx/xlnx_event_manager.c | 25 ++++++++++++++++++++-----
> > > >    include/linux/firmware/xlnx-zynqmp.h    | 16 ++++++++++++----
> > > >    3 files changed, 33 insertions(+), 10 deletions(-)
> > > >
> > > > diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
> > > > index 5f40288f69a9..6583efa9ac48 100644
> > > > --- a/drivers/firmware/xilinx/zynqmp.c
> > > > +++ b/drivers/firmware/xilinx/zynqmp.c
> > > > @@ -2019,7 +2019,7 @@ static int zynqmp_firmware_probe(struct platform_device *pdev)
> > > >    	np = of_find_compatible_node(NULL, NULL, "xlnx,versal");
> > > >    	if (np) {
> > > >    		em_dev = platform_device_register_data(&pdev->dev, "xlnx_event_manager",
> > > > -						       -1, NULL, 0);
> > > > +						       -1, &pm_sub_family_code, 4);
> > > >    		if (IS_ERR(em_dev))
> > > >    			dev_err_probe(&pdev->dev, PTR_ERR(em_dev), "EM register fail with error\n");
> > > >    	}
> > > > diff --git a/drivers/soc/xilinx/xlnx_event_manager.c b/drivers/soc/xilinx/xlnx_event_manager.c
> > > > index 38cfc161a713..8074ded7b39c 100644
> > > > --- a/drivers/soc/xilinx/xlnx_event_manager.c
> > > > +++ b/drivers/soc/xilinx/xlnx_event_manager.c
> > > > @@ -23,6 +23,7 @@ static DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number1);
> > > >    static int virq_sgi;
> > > >    static int event_manager_availability = -EACCES;
> > > > +static u32 pm_sub_family_code;
> > >
> > > Why is this not a per-device variable?  Global variables like this for
> > > drivers are almost always wrong.
> >
> > Not sure I get what you mean by per-device. Can you please elaborate on it?
>
> It should not be a global variable (i.e. the same for all devices in the
> system.)

You are not changing silicon when you run OS. It means strictly speaking you are 
not changing sub family silicon code.


> > This is the part of firmware infrastructure and there is only one instance
> > of the driver in the system registered from firmware driver itself.
>
> Then that should be fixed.
>
> > If this should be done in a generic way then there are much more variables
> > which should be moved to driver data not just this one.
>
> Agreed, they should all be moved there.

Let us to take a look at what can be done to try to remove all of them.

Jay: Can you please remove this patch from this series and let's deal with it 
separately?

Greg: Are you fine with others?

Thanks,
Michal