Re: [PATCH v8] i2c: virtio: add a virtio i2c frontend driver
flat view
From: Jie Deng <hidden>
Date: 2021-03-19 05:32:37
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linux-i2c, lkml
On 2021/3/19 11:54, Viresh Kumar wrote:
On 18-03-21, 15:52, Arnd Bergmann wrote:quoted
Allowing multiple virtio-i2c controllers in one system, and multiple i2c devices attached to each controller is clearly something that has to work.Good.quoted
I don't actually see a limitation though. Viresh, what is the problem you see for having multiple controllers?I thought this would be a problem in that case as we are using the global virtio_adapter here. + vi->adap = &virtio_adapter; + i2c_set_adapdata(vi->adap, vi); Multiple calls to probe() will end up updating the same pointer inside adap. + vi->adap->dev.parent = &vdev->dev; Same here, overwrite. + /* Setup ACPI node for controlled devices which will be probed through ACPI */ + ACPI_COMPANION_SET(&vi->adap->dev, ACPI_COMPANION(pdev)); + vi->adap->timeout = HZ / 10; These may be fine, but still not ideal I believe. + ret = i2c_add_adapter(vi->adap); i This should be a problem as well, we must be adding this to some sort of list, doing some RPM stuff, etc ? Jie, the solution is to allocate memory for adap at runtime in probe and remove the virtio_adapter structure completely.
If you want to support that. Then I think we don't need to change the following at all.
quoted hunk
+ .algo = &virtio_algorithm, + + return ret; + + vi->adap = virtio_adapter;
This is strange, why are you allocating memory for adapter twice ? Once for virtio_adapter and once for vi->adap ? Either fill the fields directly for v->adap here and remove virtio_adapter or make vi->adap a pointer. _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization