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

Wenbin Yao posted 2 patches 11 months, 2 weeks ago
There is a newer version of this series
drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 86 +++++++++++++++++-------
1 file changed, 63 insertions(+), 23 deletions(-)
[PATCH v5 0/2] phy: qcom: qmp-pcie: Add PCIe PHY no_csr reset support
Posted by Wenbin Yao 11 months, 2 weeks ago
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
-- 
2.34.1
Re: [PATCH v5 0/2] phy: qcom: qmp-pcie: Add PCIe PHY no_csr reset support
Posted by Wenbin Yao (Consultant) 11 months ago
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?

-- 
With best wishes
Wenbin
Re: [PATCH v5 0/2] phy: qcom: qmp-pcie: Add PCIe PHY no_csr reset support
Posted by Vinod Koul 11 months ago
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
Re: [PATCH v5 0/2] phy: qcom: qmp-pcie: Add PCIe PHY no_csr reset support
Posted by Manivannan Sadhasivam 11 months ago
On Tue, Mar 11, 2025 at 01:29:15AM +0530, Vinod Koul wrote:
> 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 tested the previous version and it worked well on X1P40100-CRD. Will give this
version a go and give my tag.

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

In that case, someone should add the PHY init sequence to the driver. That's why
I wanted to have the check in place to avoid silently failing PHY
initialization. Right now, the driver will error out if there is no init
sequence available.

- Mani

-- 
மணிவண்ணன் சதாசிவம்
Re: [PATCH v5 0/2] phy: qcom: qmp-pcie: Add PCIe PHY no_csr reset support
Posted by Konrad Dybcio 11 months ago
On 3/14/25 3:54 PM, Manivannan Sadhasivam wrote:
> On Tue, Mar 11, 2025 at 01:29:15AM +0530, Vinod Koul wrote:
>> 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 tested the previous version and it worked well on X1P40100-CRD. Will give this
> version a go and give my tag.
> 
>> I am also concerned about bootloader assumptions esp if the Qcom boot
>> chain is skipped

If any major part of this boot chain is skipped, much of the platform will
unfortunately not behave as expected by the kernel today, anyway. While I
personally enjoy hacking on such things, holding back hw support because of
theoretical issues is not going to help here, especially since the tables
can be trivially added at a later point, if ever needed, without requiring
DT changes.

> In that case, someone should add the PHY init sequence to the driver. That's why
> I wanted to have the check in place to avoid silently failing PHY
> initialization. Right now, the driver will error out if there is no init
> sequence available.

IIUC we internally settled on not sending the sequences for X1P4, since
the PHYs are initialized as expected.

Konrad