[PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver

Sinan Kaya
2016-01-20T22:18:29Z

Mark,

On 1/15/2016 11:01 AM, Sinan Kaya wrote:
>> I'm concerned with how this is safe, and with the userspace interface.
>> > e.g. if the user wants to up the QoS for a VM, how to they find the
>> > right channel in sysfs to alter?
> The HW supports changing the QoS values on the flight. In order to locate the
> object, I'm exporting a
>
> I tried to address your concern on v10 last series. Here is brief summary.
>
> Each channel device has a sysfs entry named chid.
> What: /sys/devices/platform/hidma-*/chid
> + /sys/devices/platform/QCOM8061:*/chid
>
>
> Each management object has one priority and weight file per channel.
> +What: /sys/devices/platform/hidma-mgmt*/chanops/chan*/priority
> + /sys/devices/platform/QCOM8060:*/chanops/chan*/priority
>
> Suppose you want to change the priority of a channel you assigned to guess,
> the userspace application goes and reads the chid value of the channel.
>
> Then goes to chanops/chan<chid>/ directory and can change priority and weight
> parameters here.
>
> Here is how the directory looks like. QCOM8060:00 is a management object.
> QCOM8061:0x are the channel objects.
>
> /sys/devices/platform/QCOM8060:00# ls
> QCOM8061:00
> QCOM8061:01
> QCOM8061:02
> QCOM8061:03
> QCOM8061:04
> QCOM8061:05
> chanops
> <other common attributes>
>
>
>
>

Did this answer your question?

I'm capturing all the questions and answers as FAQ into the cover letter as I keep
repeating myself for every single reviewer.

Besides from the "lack of documentation", is there any code related change you'd like to
discuss in the series.

--
Sinan Kaya