Re: [PATCH v5 0/2] phy: qcom: qmp-pcie: Add PCIe PHY no_csr reset support

[Vinod Koul <vkoul@kernel.org>]

On 10-03-25, 16:58, Wenbin Yao (Consultant) wrote:
> On 2/26/2025 6:35 PM, Wenbin Yao wrote:
> > The series aims to skip phy register programming and drive PCIe PHY with
> > register setting programmed in bootloader by simply toggling no_csr reset,
> > which once togglled, PHY hardware will be reset while PHY registers are
> > retained.
> > 
> > First, determine whether PHY setting can be skipped by checking
> > QPHY_START_CTRL register and the existence of nocsr reset. If it is
> > programmed and no_csr reset is supported, do no_csr reset and skip BCR
> > reset which will reset entire PHY.
> > 
> > This series also remove has_nocsr_reset flag in qmp_phy_cfg structure and
> > decide whether the PHY supports nocsr reset by checking the existence of
> > nocsr reset in device tree.
> > 
> > The series are tested on X1E80100-QCP and HDK8550.
> > 
> > The commit messages of this patchset have been modified based on comments
> > and suggestions.
> > 
> > Changes in v5:
> > - Add a check whether the init sequences are exist if the PHY needs to be
> >    initialized to Patch 2/2.
> > - Link to v4: https://lore.kernel.org/all/20250220102253.755116-1-quic_wenbyao@quicinc.com/
> > 
> > Changes in v4:
> > - Add Philipp's Reviewed-by tag to Patch 1/2.
> > - Use PHY instead of phy in comments in Patch 2/2.
> > - Use "if (qmp->nocsr_reset)" instead of "if (!qmp->nocsr_reset)" in
> >    function qmp_pcie_exit for readability in Patch 2/2.
> > - Use goto statements in function qmp_pcie_power_on and qmp_pcie_power_off
> >    for readability in Patch 2/2.
> > - Refine the comment of why not checking qmp->skip_init when reset PHY in
> >    function qmp_pcie_power_off in Patch 2/2.
> > - Link to v3: https://lore.kernel.org/all/20250214104539.281846-1-quic_wenbyao@quicinc.com/
> > 
> > Changes in v3:
> > - Replace devm_reset_control_get_exclusive with
> >    devm_reset_control_get_optional_exclusive when get phy_nocsr reset
> >    control in Patch 1/2.
> > - Do not ignore -EINVAL when get phy_nocsr reset control in Patch 1/2.
> > - Replace phy_initialized with skip_init in struct qmp_pcie in Patch 2/2.
> > - Add a comment to why not check qmp->skip_init in function
> >    qmp_pcie_power_off in Patch 2/2.
> > - Link to v2: https://lore.kernel.org/all/20250211094231.1813558-1-quic_wenbyao@quicinc.com/
> > 
> > Changes in v2:
> > - Add Abel's and Manivannan's Reviewed-by tag to Patch 1/2.
> > - Refine commit msg of Patch 2/2.
> > - Link to v1: https://lore.kernel.org/all/20250121094140.4006801-1-quic_wenbyao@quicinc.com/
> > 
> > Konrad Dybcio (1):
> >    phy: qcom: pcie: Determine has_nocsr_reset dynamically
> > 
> > Qiang Yu (1):
> >    phy: qcom: qmp-pcie: Add PHY register retention support
> > 
> >   drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 86 +++++++++++++++++-------
> >   1 file changed, 63 insertions(+), 23 deletions(-)
> > 
> > 
> > base-commit: bcf2acd8f64b0a5783deeeb5fd70c6163ec5acd7
> 
> Hi, do you have any futher comments?

Patches lgtm, It would be great if this was tested by someone as well...
Abel, Stephan, Neil can you folks test this and provide T-B

I am also concerned about bootloader assumptions esp if the Qcom boot
chain is skipped

-- 
~Vinod

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