linux-kernel - Re: [PATCH v2 1/4] regulator: rpmh-regulator: Fix PMIC5 BOB bypass mode handling

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Message-ID: <20251024080358.rkebbvg7louwbo6k@hu-kamalw-hyd.qualcomm.com>
Date: Fri, 24 Oct 2025 13:33:58 +0530
From: Kamal Wadhwa <kamal.wadhwa@....qualcomm.com>
To: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
Cc: Mark Brown <broonie@...nel.org>,
        Konrad Dybcio <konrad.dybcio@....qualcomm.com>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>,
        Liam Girdwood <lgirdwood@...il.com>, linux-arm-msm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/4] regulator: rpmh-regulator: Fix PMIC5 BOB bypass
 mode handling

On Thu, Oct 23, 2025 at 02:37:07PM +0300, Dmitry Baryshkov wrote:
> On Wed, Oct 22, 2025 at 04:15:51PM +0100, Mark Brown wrote:
> > On Wed, Oct 22, 2025 at 06:11:46PM +0300, Dmitry Baryshkov wrote:
> > > On Wed, Oct 22, 2025 at 04:58:15PM +0200, Konrad Dybcio wrote:
> > > > On 10/22/25 12:23 AM, Dmitry Baryshkov wrote:
> > > > > On Wed, Oct 22, 2025 at 02:38:53AM +0530, Kamal Wadhwa wrote:
> > 
> > > > >> Currently, when `rpmh_regulator_set_mode_bypass()` helper function
> > > > >> is called to set bypass mode, it sends PMIC4's BOB bypass mode
> > > > >> value for even if its a PMIC5 BOB.
> > 
> > > > > The universe will end, the Sun will explode and Ragnarök will be upon
> > > > > us. Please describe the issue, why sending bypass value is bad.
> > 
> > > > I think you misread, it sends the magic value which corresponds
> > > > to BYPASS, but one that worked for the previous generation
> > 
> > > I just wanted to point out that the commit message makes a statement
> > > that it sends some value. It should document, why the sent value is bad.
> > 
> > It seems fairly clear to me from the above that the driver is sending
> > the value for the wrong device type which is something so obviously
> > wrong I'm not sure it requires further explanation.
> 
> Okay. I'm sorry if I'm overreacting.
> 
> The bypass_supported field still needs to go away in my opinion.

@Dmitry - one way to avoid it is if i re-use `.pmic_bypass_mode` and
keep it  `= -EINVAL` for the checking if the bypass mode is not
supported? and drop the `.bypass_supported`.

But do note that currently only BOB type regulator supports bypass
mode, and this above change will also require modifying all of the
existing (and future) configs for regulator types that do not support
bypass control.

In all below 28 structures we will have to define
`.pmic_bypass_mode = -EINVAL` 

static const struct rpmh_vreg_hw_data pmic4_pldo = {
static const struct rpmh_vreg_hw_data pmic4_pldo_lv = {
static const struct rpmh_vreg_hw_data pmic4_nldo = {
static const struct rpmh_vreg_hw_data pmic4_hfsmps3 = {
static const struct rpmh_vreg_hw_data pmic4_ftsmps426 = {
static const struct rpmh_vreg_hw_data pmic4_lvs = {
static const struct rpmh_vreg_hw_data pmic5_pldo = {
static const struct rpmh_vreg_hw_data pmic5_pldo_lv = {
static const struct rpmh_vreg_hw_data pmic5_pldo515_mv = {
static const struct rpmh_vreg_hw_data pmic5_pldo502 = {
static const struct rpmh_vreg_hw_data pmic5_pldo502ln = {
static const struct rpmh_vreg_hw_data pmic5_nldo = {
static const struct rpmh_vreg_hw_data pmic5_nldo515 = {
static const struct rpmh_vreg_hw_data pmic5_nldo502 = {
static const struct rpmh_vreg_hw_data pmic5_hfsmps510 = {
static const struct rpmh_vreg_hw_data pmic5_ftsmps510 = {
static const struct rpmh_vreg_hw_data pmic5_ftsmps520 = {
static const struct rpmh_vreg_hw_data pmic5_ftsmps525 = {
static const struct rpmh_vreg_hw_data pmic5_ftsmps527 = {
static const struct rpmh_vreg_hw_data pmic5_hfsmps515 = {
static const struct rpmh_vreg_hw_data pmic5_hfsmps515_1 = {
static const struct rpmh_vreg_hw_data pmic5_nldo530 = {
static const struct rpmh_vreg_hw_data pmic5_pldo530_mvp150 = {
static const struct rpmh_vreg_hw_data pmic5_pldo530_mvp300 = {
static const struct rpmh_vreg_hw_data pmic5_pldo530_mvp600 = {
static const struct rpmh_vreg_hw_data pmic5_ftsmps530 = {

while in the current patch i dont need to touch any of these above
structures and just add new property and define it whereever
`bypass_supported` is set to true.

i.e just change these 2 bob nodes only.

static const struct rpmh_vreg_hw_data pmic5_bob = {
static const struct rpmh_vreg_hw_data pmic4_bob = {

Please suggest, if we can do this in a better way.

Regards,
Kamal