On 13/09/2023 13:58, Mark Brown wrote:
On Wed, Sep 13, 2023 at 12:56:03PM +0200, Amadeusz Sławiński wrote:
On 9/12/2023 6:32 PM, Richard Fitzgerald wrote:
+#ifdef CONFIG_PCI
- /*
* PCI does not define 0 as invalid, so pci_subsystem_set indicates* whether a value has been written to these fields.*/- unsigned short pci_subsystem_vendor;
- unsigned short pci_subsystem_device;
- bool pci_subsystem_set;
+#endif /* CONFIG_PCI */
- char topology_shortname[32]; struct device *dev;
This looks bit weird to me, snd_soc_card is _generic_ struct which is not device specific in any way, and now you add fields for PCI, can't this somehow be done using drvdata or something?
You're right that it's a bit messy but if we use driver data then it becomes specific to a particular driver and there's a goal here to share with subfunction drivers. I was thinking we could refactor to a union or otherwise extend if we find other users with a similar need.
Yes, I was trying to avoid multiple custom ways of passing the same data around. A significant advantage of explicitly passing the SSID (if it's available) rather than a more abstract identifier (such as a char *) is that's it's very well defined exactly what a PCI SSID is so we know we can use it verbatim. A more abstract identifier creates an implied trust (or mistrust) between the machine driver and the component receiving it whether it's unique and in a useful format.
I could de-ugly it a bit by moving it out into a separate struct/union and having just a member of that struct type in snd_soc_card.
An alternative was to add a function like the existing snd_soc_component_set_whatever() family but that means adding a callback pointer to struct snd_soc_component_driver, which is creating more space overhead than one value in the snd_soc_card.