Re: [PATCH] s390/ism: Add check for dma_set_max_seg_size in ism_probe()

[Markus Elfring]

> > As the possible failure of the dma_set_max_seg_size(), we should
> > better check the return value of the dma_set_max_seg_size().
>
> I think formally you're correct. dma_set_max_seg_size() could return an
> error if dev->dma_parms was not present.
>
> However, since ISM devices are PCI attached (and will remain PCI
> attached I believe) we can take the existance of dev->dma_parms for
> granted since pci_device_add() (in drivers/pci/probe.c) will make that
> point to the pci_dev's dma_parms for every PCI device.
>
> So I'm not sure how important this fix is.

Another function call can fail eventually.

dma_set_seg_boundary()
https://elixir.bootlin.com/linux/v6.10-rc5/source/include/linux/dma-mapping.h#L562

Will it become relevant to complete the error detection
and corresponding exception handling any further?

Regards,
Markus