On 7/29/2021 9:37 PM, Doug Anderson wrote:
Hi,
On Thu, Jul 29, 2021 at 5:01 AM Rajendra Nayak <rnayak@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx>
---
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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