Re: [PATCH 5/8] thermal:cpu cooling:tegra: Provide deferred probing for tegra driver

From: Mikko Perttunen
Date: Fri Nov 14 2014 - 05:47:51 EST


Tested-by: Mikko Perttunen <mikko.perttunen@xxxxxxxx>

One potential issue I can see is that if the cpufreq driver fails to probe then you'll never get the thermal driver either. For example, Tegra124 currently has no cpufreq driver, so if CONFIG_CPU_THERMAL was enabled, then the soctherm driver would never be able to probe. But I don't really have a solution for this either.

Cheers,
Mikko

On 11/13/2014 07:02 PM, Lukasz Majewski wrote:
When CPU freq is used as a thermal zone cooling device, one needs to wait
until cpufreq subsystem is properly initialized.

This code is similar to the one already available in imx_thermal.c file.

Signed-off-by: Lukasz Majewski <l.majewski@xxxxxxxxxxx>
---
drivers/thermal/tegra_soctherm.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/thermal/tegra_soctherm.c b/drivers/thermal/tegra_soctherm.c
index 70f7e9e..9c5aaa4 100644
--- a/drivers/thermal/tegra_soctherm.c
+++ b/drivers/thermal/tegra_soctherm.c
@@ -26,6 +26,7 @@
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/thermal.h>
+#include <linux/cpufreq.h>

#include <soc/tegra/fuse.h>

@@ -346,6 +347,12 @@ static int tegra_soctherm_probe(struct platform_device *pdev)

const struct tegra_tsensor *tsensors = t124_tsensors;

+#ifdef CONFIG_CPU_THERMAL
+ if (!cpufreq_get_current_driver()) {
+ dev_dbg(&pdev->dev, "no cpufreq driver!");
+ return -EPROBE_DEFER;
+ }
+#endif
tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
if (!tegra)
return -ENOMEM;


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