Re: [PATCH v1 11/30] drm/tegra: dc: Support OPP and SoC core voltage scaling

10.11.2020 23:29, Thierry Reding пишет:

...

• dc->opp_table = dev_pm_opp_get_opp_table(dc->dev);
• if (IS_ERR(dc->opp_table))

• return dev_err_probe(dc->dev, PTR_ERR(dc->opp_table),
  

• 		     "failed to prepare OPP table\n");
  

• if (of_machine_is_compatible("nvidia,tegra20"))

• hw_version = BIT(tegra_sku_info.soc_process_id);
  

• else

• hw_version = BIT(tegra_sku_info.soc_speedo_id);
  

• hw_opp_table = dev_pm_opp_set_supported_hw(dc->dev, &hw_version, 1);
• err = PTR_ERR_OR_ZERO(hw_opp_table);

What's the point of this? A more canonical version would be:

if (IS_ERR(hw_opp_table)) { err = PTR_ERR(hw_opp_table); dev_err(dc->dev, ...); goto put_table; }

That uses the same number of lines but is much easier to read, in my opinion, because it is the canonical form.

Your variant is much more difficult to read for me :/

I guess the only reason it could be "canonical" is because PTR_ERR_OR_ZERO was added not so long time ago.

But don't worry, this code will be moved out in a v2 and it won't use PTR_ERR_OR_ZERO.