Re: [RESEND PATCH v8 0/3] Add Intel ComboPhy driver

[Dilip Kota]

On 5/18/2020 9:49 PM, Kishon Vijay Abraham I wrote:
> Dilip,
>
> On 5/15/2020 1:43 PM, Dilip Kota wrote:
> > This patch series adds Intel ComboPhy driver, respective yaml schemas
> >
> > Changes on v8:
> >    As per PHY Maintainer's request add description in comments for doing
> >    register access through register map framework.
> >
> > Changes on v7:
> >    As per System control driver maintainer's inputs remove
> >      fwnode_to_regmap() definition and use device_node_get_regmap()
> Can you fix this warning and resend the patch?
> drivers/phy/intel/phy-intel-combo.c:229:6: warning: âcb_modeâ may be used
> uninitialized in this function [-Wmaybe-uninitialized]
>    ret = regmap_write(cbphy->hsiocfg, REG_COMBO_MODE(cbphy->bid), cb_mode);
>    ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/phy/intel/phy-intel-combo.c:204:24: note: âcb_modeâ was declared here
>    enum intel_combo_mode cb_mode;
>                          ^~~~~~~
I noticed this warning while preparing the patch.
It sounds like false warning because:
1.) "cb_mode" is initialized in the switch case based on the "mode = 
cbphy->phy_mode;"
2.) cbphy->phy_mode is initialized during the probe in 
"intel_cbphy_fwnode_parse()" with one of the 3 values.
PHY_PCIE_MODE, PHY_SATA_MODE, PHY_XPCS_MODE.
3.) There is no chance of "cbphy->phy_mode" having different value.
4.) And "cb_mode" will be initialized according to the "mode = 
cbphy->phy_mode;"
5.) Hence, there is no chance of "cb_mode" getting accessed uninitialized.

Regards,
Dilip
> Thanks
> Kishon
> >      
> > Changes on v6:
> >    Rebase patches on the latest maintainer's branch
> >    https://git.kernel.org/pub/scm/linux/kernel/git/kishon/linux-phy.git/?h=phy-for-5.7
> > Dilip Kota (3):
> >    dt-bindings: phy: Add PHY_TYPE_XPCS definition
> >    dt-bindings: phy: Add YAML schemas for Intel ComboPhy
> >    phy: intel: Add driver support for ComboPhy
> >
> >   .../devicetree/bindings/phy/intel,combo-phy.yaml   | 101 ++++
> >   drivers/phy/intel/Kconfig                          |  14 +
> >   drivers/phy/intel/Makefile                         |   1 +
> >   drivers/phy/intel/phy-intel-combo.c                | 632 +++++++++++++++++++++
> >   include/dt-bindings/phy/phy.h                      |   1 +
> >   5 files changed, 749 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/phy/intel,combo-phy.yaml
> >   create mode 100644 drivers/phy/intel/phy-intel-combo.c