Messages in this thread | | | Subject | Re: [PATCH v2 2/3] nvmem: qfprom: sc7280: Handle the additional power-domains vote | From | Rajendra Nayak <> | Date | Fri, 30 Jul 2021 11:25:26 +0530 |
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On 7/29/2021 9:37 PM, Doug Anderson wrote: > Hi, > > On Thu, Jul 29, 2021 at 5:01 AM Rajendra Nayak <rnayak@codeaurora.org> wrote: >> >> On sc7280, to reliably blow fuses, we need an additional vote >> on max performance state of 'MX' power-domain. >> Add support for power-domain performance state voting in the >> driver. >> >> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org> >> --- >> drivers/nvmem/qfprom.c | 26 ++++++++++++++++++++++++++ >> 1 file changed, 26 insertions(+) >> >> diff --git a/drivers/nvmem/qfprom.c b/drivers/nvmem/qfprom.c >> index 81fbad5..b5f27df 100644 >> --- a/drivers/nvmem/qfprom.c >> +++ b/drivers/nvmem/qfprom.c >> @@ -12,6 +12,8 @@ >> #include <linux/mod_devicetable.h> >> #include <linux/nvmem-provider.h> >> #include <linux/platform_device.h> >> +#include <linux/pm_domain.h> >> +#include <linux/pm_runtime.h> >> #include <linux/property.h> >> #include <linux/regulator/consumer.h> >> >> @@ -139,6 +141,9 @@ static void qfprom_disable_fuse_blowing(const struct qfprom_priv *priv, >> { >> int ret; >> >> + dev_pm_genpd_set_performance_state(priv->dev, 0); >> + pm_runtime_put(priv->dev); > > To me it feels as if this should be at the end of the function rather > than the beginning. I guess it doesn't matter (?), but it feels wrong > that we have writes to the register space after we're don't a > pm_runtime_put().
Right, I was confused with this too when I saw that the other resources (regulator/clocks) were also turned off before we write into the register space. And then looking into the driver I realized its perhaps because the resources are needed only for the 'raw' writes and the 'conf' read/writes can happen regardless. I'll just fix that up and put the register writes before we really turn off any resources to avoid confusion.
> > >> @@ -420,6 +440,12 @@ static int qfprom_probe(struct platform_device *pdev) >> econfig.reg_write = qfprom_reg_write; >> } >> >> + ret = devm_add_action_or_reset(dev, qfprom_runtime_disable, dev); >> + if (ret) >> + return ret; >> + >> + pm_runtime_enable(dev); >> + > > Swap the order of the two. IOW first pm_runtime_enable(), then > devm_add_action_or_reset(). Specifically the "_or_reset" means that if > you fail to add the action (AKA devm_add_action() fails to allocate > the tiny amount of memory it needs) it will actually _call_ the > action.
Ah, I didn't know that, thanks, I'll fix the order up and repost.
> That means that in your code if the memory allocation fails > you'll call pm_runtime_disable() without the corresponding > pm_runtime_enable(). > > > Other than those two issues this looks good to me. Feel free to add my > Reviewed-by when you fix them.
Thanks.
> > -Doug >
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