intel_th: Skip subdevices if their MMIO is missing (23f66749) · Commits · 戴 / test

If a subdevice requires an MMIO region that wasn't in the resources passed down from the glue layer, don't instantiate it, but don't error out. This means that that particular subdevice doesn't exist for this instance of Intel TH, which is a perfectly normal situation. This applies, for example, to the "rtit" source device. Signed-off-by:

Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/intel_th/core.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -607,6 +607,9 @@ intel_th_subdevice_alloc(struct intel_th *th,
		*/
		if (!res[r].end && res[r].flags == IORESOURCE_MEM) {
		bar = res[r].start;
		err = -ENODEV;
		if (bar >= th->num_resources)
		goto fail_put_device;
		res[r].start = 0;
		res[r].end = resource_size(&devres[bar]) - 1;
		}
		@@ -749,8 +752,13 @@ static int intel_th_populate(struct intel_th *th)

		thdev = intel_th_subdevice_alloc(th, subdev);
		/* note: caller should free subdevices from th::thdev[] */
		if (IS_ERR(thdev))
		if (IS_ERR(thdev)) {
		/* ENODEV for individual subdevices is allowed */
		if (PTR_ERR(thdev) == -ENODEV)
		continue;

		return PTR_ERR(thdev);
		}

		th->thdev[th->num_thdevs++] = thdev;
		}
		@@ -813,9 +821,6 @@ intel_th_alloc(struct device dev, struct intel_th_drvdata drvdata,
		struct intel_th *th;
		int err, r;

		if (ndevres < TH_MMIO_END)
		return ERR_PTR(-EINVAL);

		th = kzalloc(sizeof(*th), GFP_KERNEL);
		if (!th)
		return ERR_PTR(-ENOMEM);

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