RE: [PATCH v1 0/5] PCI: qcom: rework pipe_clk/pipe_clk_src handling

["Prasad Malisetty (Temp) (QUIC)" <quic_pmaliset@quicinc.com>]

Hi Dmitry,

Please find inline comments below.

Thanks
-Prasad

> -----Original Message-----
> From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Sent: Wednesday, March 30, 2022 6:26 PM
> To: Prasad Malisetty (Temp) (QUIC) <quic_pmaliset@quicinc.com>; Andy Gross
> <agross@kernel.org>; bjorn.andersson@linaro.org; Stephen Boyd
> <swboyd@chromium.org>; Michael Turquette <mturquette@baylibre.com>;
> Taniya Das <tdas@codeaurora.org>; Lorenzo Pieralisi
> <lorenzo.pieralisi@arm.com>; Krzysztof Wilczyński <kw@linux.com>; Bjorn
> Helgaas <bhelgaas@google.com>
> Cc: linux-arm-msm@vger.kernel.org; linux-clk@vger.kernel.org; linux-
> pci@vger.kernel.org
> Subject: Re: [PATCH v1 0/5] PCI: qcom: rework pipe_clk/pipe_clk_src handling
> 
> On 23/03/2022 11:50, Dmitry Baryshkov wrote:
> > PCIe pipe clk (and some other clocks) must be parked to the "safe"
> > source (bi_tcxo) when corresponding GDSC is turned off and on again.
> > Currently this is handcoded in the PCIe driver by reparenting the
> > gcc_pipe_N_clk_src clock.
> >
> > Instead of doing it manually, follow the approach used by
> > clk_rcg2_shared_ops and implement this parking in the enable() and
> > disable() clock operations for respective pipe clocks.
> 
> Prasad, can we please get your comments on this patchset?
> Since you have submitted original patchset for sc7280, it looks like you should be
> interested in testing that this patchset doesn't break your devices.
> 
Thanks for optimizing pipe clock handling. 
Sure Dmitry, the validation is in progress ( Need to validate power consumption and other stuff).
I will update once done.

Thanks,
-Prasad.
> >
> > Changes since RFC:
> >   - Rework clk-regmap-mux fields. Specify safe parent as P_* value rather
> >     than specifying the register value directly
> >   - Expand commit message to the first patch to specially mention that
> >     it is required only on newer generations of Qualcomm chipsets.
> >
> > Dmitry Baryshkov (5):
> >    clk: qcom: regmap-mux: add pipe clk implementation
> >    clk: qcom: gcc-sm8450: use new clk_regmap_mux_safe_ops for PCIe pipe
> >      clocks
> >    clk: qcom: gcc-sc7280: use new clk_regmap_mux_safe_ops for PCIe pipe
> >      clocks
> >    PCI: qcom: Remove unnecessary pipe_clk handling
> >    PCI: qcom: Drop manual pipe_clk_src handling
> >
> >   drivers/clk/qcom/clk-regmap-mux.c      | 78 +++++++++++++++++++++++
> >   drivers/clk/qcom/clk-regmap-mux.h      |  3 +
> >   drivers/clk/qcom/gcc-sc7280.c          |  6 +-
> >   drivers/clk/qcom/gcc-sm8450.c          |  6 +-
> >   drivers/pci/controller/dwc/pcie-qcom.c | 87 +-------------------------
> >   5 files changed, 92 insertions(+), 88 deletions(-)
> >
> 
> 
> --
> With best wishes
> Dmitry