linux-kernel - Re: [RFC PATCH v8 05/10] cxl/memscrub: Add CXL device patrol scrub control feature

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Message-ID: <20240429132133.0000606c@Huawei.com>
Date: Mon, 29 Apr 2024 13:21:33 +0100
From: Jonathan Cameron <Jonathan.Cameron@...wei.com>
To: Shiju Jose <shiju.jose@...wei.com>
CC: fan <nifan.cxl@...il.com>, "linux-cxl@...r.kernel.org"
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Subject: Re: [RFC PATCH v8 05/10] cxl/memscrub: Add CXL device patrol scrub
 control feature


> >> diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index
> >> 0c79d9ce877c..399e43463626 100644
> >> --- a/drivers/cxl/mem.c
> >> +++ b/drivers/cxl/mem.c
> >> @@ -117,6 +117,12 @@ static int cxl_mem_probe(struct device *dev)
> >>  	if (!cxlds->media_ready)
> >>  		return -EBUSY;
> >>
> >> +	rc = cxl_mem_patrol_scrub_init(cxlmd);
> >> +	if (rc) {
> >> +		dev_dbg(&cxlmd->dev, "CXL patrol scrub init failed\n");
> >> +		return rc;
> >> +	}  
> >
> >If the device does not support memory patrol scrub feature, the above function
> >will return -EOPNOTSUPP. Since the feature is optional, should we just warn it
> >and let it go through?  
> Feedback from Jonathan was that, if this feature is built in, then should not proceed
> if the patrol scrub init failed, though it is an optional feature.

Oops. That wasn't my intent.  If the feature is implemented by the hardware and
init fails, then I think we should fail probe.  Or maybe just print a very shouty
message about it being broken.  If the feature is simply not implemented we
should definitely not fail.

Jonathan

>  
> >
> >Fan  
> >> +
> >>  	/*
> >>  	 * Someone is trying to reattach this device after it lost its port
> >>  	 * connection (an endpoint port previously registered by this memdev
> >> was
> >> --
> >> 2.34.1
> >>  
> Thanks,
> Shiju