[PATCH 2/3] cxl: Introduce module parameter 'enable_psltrace'

[christophe lombard]

Le 09/02/2018 à 05:25, Vaibhav Jain a écrit :
> We introduce a new module parameter named 'enable_psltrace' which asks cxl
> to start(by default) psl-traces on an adapter as soon as its probe is
> finished. In case this default behavior is not needed then this
> module parameter can be set to '0'.
> 
> Signed-off-by: Vaibhav Jain <vaibhav at linux.vnet.ibm.com>
> ---
>   drivers/misc/cxl/cxl.h  | 2 ++
>   drivers/misc/cxl/main.c | 4 ++++
>   drivers/misc/cxl/pci.c  | 3 +++
>   3 files changed, 9 insertions(+)
> 
> diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
> index 81da307b60c0..1af66451cbb4 100644
> --- a/drivers/misc/cxl/cxl.h
> +++ b/drivers/misc/cxl/cxl.h
> @@ -28,6 +28,7 @@
>   #include <uapi/misc/cxl.h>
> 
>   extern uint cxl_verbose;
> +extern bool cxl_enable_psltrace;
> 
>   #define CXL_TIMEOUT 5
> 
> @@ -678,6 +679,7 @@ struct cxl_service_layer_ops {
>   	void (*psl_irq_dump_registers)(struct cxl_context *ctx);
>   	void (*err_irq_dump_registers)(struct cxl *adapter);
>   	void (*stop_psltrace)(struct cxl *adapter);
> +	void (*start_psltrace)(struct cxl *adapter);
>   	void (*write_timebase_ctrl)(struct cxl *adapter);
>   	u64 (*timebase_read)(struct cxl *adapter);
>   	int capi_mode;
> diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c
> index c1ba0d42cbc8..593f2cdba3d8 100644
> --- a/drivers/misc/cxl/main.c
> +++ b/drivers/misc/cxl/main.c
> @@ -34,6 +34,10 @@ uint cxl_verbose;
>   module_param_named(verbose, cxl_verbose, uint, 0600);
>   MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
> 
> +bool cxl_enable_psltrace = true;
> +module_param_named(enable_psltrace, cxl_enable_psltrace, bool, 0600);
> +MODULE_PARM_DESC(enable_psltrace, "Set PSL traces on probe. default: on");
> +
I am not too agree to add a new parameter. This can cause doubts.
PSL team has confirmed that enabling traces has no impact.
Do you see any reason to disable the traces ?

>   const struct cxl_backend_ops *cxl_ops;
> 
>   int cxl_afu_slbia(struct cxl_afu *afu)
> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
> index 926b13973b73..9e8b8525534c 100644
> --- a/drivers/misc/cxl/pci.c
> +++ b/drivers/misc/cxl/pci.c
> @@ -1726,6 +1726,9 @@ static int cxl_configure_adapter(struct cxl *adapter, struct pci_dev *dev)
>   	if ((rc = cxl_native_register_psl_err_irq(adapter)))
>   		goto err;
> 
> +	if (cxl_enable_psltrace && adapter->native->sl_ops->start_psltrace)
> +		adapter->native->sl_ops->start_psltrace(adapter);
> +
>   	return 0;
> 
>   err:
>