RE: [PATCH iwlwifi-next] wifi: iwlwifi: pcie: return a real errno from read_config32()

[Gaur, Yogesh]

> -----Original Message-----
> From: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> Sent: Wednesday, October 14, 2026 6:26 PM
> To: Gaur, Yogesh <yogesh.gaur@xxxxxxxxx>; Korenblit, Miriam Rachel
> <miriam.rachel.korenblit@xxxxxxxxx>; linux-wireless@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Cc: Grumbach, Emmanuel <emmanuel.grumbach@xxxxxxxxx>
> Subject: Re: [PATCH iwlwifi-next] wifi: iwlwifi: pcie: return a real errno from
> read_config32()
> 
> On Wed, 2026-10-14 at 18:13 +0530, Yogesh Gaur wrote:
> > pci_read_config_dword() can also return a positive PCIBIOS_* error
> > code (e.g. PCIBIOS_DEVICE_NOT_FOUND for a disconnected device), but
> > iwl_trans_pcie_read_config32() passes it through unchanged and
> > iwl_dump_ini_config_iter() only checks for ret < 0. The error is
> > missed, so the loop keeps reading and stores 0xffffffff in the dump.
> >
> > Convert the return value with pcibios_err_to_errno().
> >
> 
> This isn't incorrect, but is it a good idea? I'm not convinced, we might still get
> some other parts of the dump vs. just aborting the entire section at that
> point?
> 
> IOW, _why_ are you doing this? Do you have a problem with it? What is that
> problem? Is it just a static checker/LLM complaint that you want to fix?

No real-world problem. It came out of LLM-assisted code review that flagged the positive PCIBIOS_* return being missed by the ret < 0 check;
I haven't seen it cause a failure.

Yes current behaviour is the better one for a dump: a failed range makes iwl_dump_ini_mem() drop the whole region, whereas today a misaligned offset just records 0xffffffff for that word and the rest of the region is still collected. For a disconnected device every read returns all-ones either way.

Please drop this one. Thanks for the review.

Yogesh
> 
> johannes