netdev - Re: [PATCH 6/9] ethernet: cavium: Replace deprecated PCI functions

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Message-ID: <5d70794731198ec7bc59bd95e50a8aa81cf97c7b.camel@redhat.com>
Date: Tue, 20 Aug 2024 09:40:09 +0200
From: Philipp Stanner <pstanner@...hat.com>
To: Andy Shevchenko <andy@...nel.org>
Cc: onathan Corbet <corbet@....net>, Jens Axboe <axboe@...nel.dk>, Wu Hao
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Subject: Re: [PATCH 6/9] ethernet: cavium: Replace deprecated PCI functions

On Mon, 2024-08-19 at 21:23 +0300, Andy Shevchenko wrote:
> On Mon, Aug 19, 2024 at 06:51:46PM +0200, Philipp Stanner wrote:
> > pcim_iomap_regions() and pcim_iomap_table() have been deprecated by
> > the PCI subsystem in commit e354bb84a4c1 ("PCI: Deprecate
> > pcim_iomap_table(), pcim_iomap_regions_request_all()").
> > 
> > Replace these functions with the function pcim_iomap_region().
> 
> ...
> 
> cavium_ptp_probe()
> 
> > -	pcim_iounmap_regions(pdev, 1 << PCI_PTP_BAR_NO);
> > +	pcim_iounmap_region(pdev, PCI_PTP_BAR_NO);
> >  
> >  error_free:
> >  	devm_kfree(dev, clock);
> 
> Both are questionable. Why do we need either of them?

You seem to criticize my pcim_iounmap_region() etc. in other unwind
paths, too. I think your criticism is often justified. This driver
here, however, was the one which made me suspicious and hesitate and
removing those calls; because of the code below:

	pcim_iounmap_region(pdev, PCI_PTP_BAR_NO);

error_free:
	devm_kfree(dev, clock);

error:
	/* For `cavium_ptp_get()` we need to differentiate between the case
	 * when the core has not tried to probe this device and the case when
	 * the probe failed.  In the later case we pretend that the
	 * initialization was successful and keep the error in
	 * `dev->driver_data`.
	 */
	pci_set_drvdata(pdev, ERR_PTR(err));
	return 0;
}

So in case of an error they return 0 and do... stuff.

I don't want to touch that without someone who maintains (and, ideally,
understands) the code details what's going on here.

P.