Re: [PATCH v2 2/3] nvmem: qfprom: sc7280: Handle the additional power-domains vote
From: Doug Anderson <dianders@chromium.org>
Date: 2021-07-29 16:11:08
Also in:
linux-arm-msm, lkml
Hi, On Thu, Jul 29, 2021 at 5:01 AM Rajendra Nayak [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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().
quoted hunk ↗ jump to hunk
@@ -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. 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. -Doug