Messages in this thread | | | Subject | Re: [PATCH V2 1/2] soc: qcom: aoss: Expose send for generic usecase | From | Deepak Kumar Singh <> | Date | Wed, 5 May 2021 13:14:07 +0530 |
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On 4/14/2021 2:42 AM, Bjorn Andersson wrote: > On Thu 08 Apr 23:39 CDT 2021, Deepak Kumar Singh wrote: > [..] >> +/** >> + * qmp_get() - get a qmp handle from a device >> + * @dev: client device pointer >> + * >> + * Return: handle to qmp device on success, ERR_PTR() on failure >> + */ >> +struct qmp *qmp_get(struct device *dev) >> +{ >> + struct platform_device *pdev; >> + struct device_node *np; >> + struct qmp *qmp; >> + >> + if (!dev || !dev->of_node) >> + return ERR_PTR(-EINVAL); >> + >> + np = of_parse_phandle(dev->of_node, "qcom,qmp", 0); >> + if (!np) >> + return ERR_PTR(-ENODEV); >> + >> + pdev = of_find_device_by_node(np); >> + if (!pdev) >> + return ERR_PTR(-EINVAL); >> + >> + qmp = platform_get_drvdata(pdev); >> + return qmp ? qmp : ERR_PTR(-EPROBE_DEFER); >> +} >> +EXPORT_SYMBOL(qmp_get); >> + >> +void qmp_put(struct platform_device *pdev) >> +{ >> + platform_device_put(pdev); > I was expecting that the devres allocated struct qmp would stick around > until the struct device's release callback came. As described in my > answer to Mani yesterday I was wrong. > > As such you need to make sure that struct qmp stays around until > qmp_remove() and all qmp_put() calls has been made. > > I presume a reasonable way to achieve this is to not use devm to > allocate our struct qmp, add a kref to the object. So this would have to > be a kref_put() on that instead of the platform_device_put() I asked you > to implement here. > > Sorry about that. > > > The rest of the patch looks good. > > Regards, > Bjorn
Hi Bjorn,
Even if we use kref_put(), would it not require platform_device_put()? As per my understanding of_find_device_by_node(np) will increment node/pdev kobj refcount which both needs to be decremented.
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