Messages in this thread |  | | From | "Mahapatra, Amit Kumar" <> | | Subject | RE: [PATCH v12 3/3] mtd: Add driver for concatenating devices | | Date | Tue, 13 May 2025 14:45:39 +0000 |
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[AMD Official Use Only - AMD Internal Distribution Only]
Hello Miquel,
> >> > + mtd->dev.parent = concat->subdev[0]->dev.parent; > >> > + mtd->dev = concat->subdev[0]->dev; > >> > + > >> > + /* Register the platform device */ > >> > + ret = mtd_device_register(mtd, NULL, 0); > >> > + if (ret) > >> > + goto destroy_concat; > >> > + } > >> > + > >> > + return 0; > >> > + > >> > +destroy_concat: > >> > + mtd_concat_destroy(mtd); > >> > + > >> > + return ret; > >> > +} > >> > + > >> > +late_initcall(mtd_virt_concat_create_join); > >> > >> The current implementation does not support probe deferrals, I > >> believe it should be handled. > > > > I see that the parse_mtd_partitions() API can return -EPROBE_DEFER > > during MTD device registration, but this behavior is specific to the > > parse_qcomsmem_part parser. None of the other parsers appear to > > support probe deferral. As discussed in RFC [1], the virtual concat > > feature is purely a fixed-partition capability, and based on my > > understanding, the fixed-partition parser does not support probe deferral. > > Please let me know if you can think of any other probe deferral > > scenarios that might impact the virtual concat driver. > > That's true, but I kind of dislike the late_initcall, I fear it might break in creative ways.
I understand, but since we require the partition information to be available, late_initcall seems to be the most suitable choice among the initcall levels—if we decide to proceed with using an initcall. Regarding potential failures, as far as I can tell, the operation would fail if, at the time of concatenation, one or more of the MTD devices involved in the concat are not yet available. In such a scenario, we can issue a kernel warning and exit gracefully. But, However, if you prefer to move away from using initcalls and have an alternative implementation approach in mind, please let us know.
Regards, Amit > > Thanks, > Miquèl
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