RE: [EXT] Re: [PATCH v4 1/2] arm64: dts: imx8-ss-img: Assign slot for imx jpeg encoder/decoder

From: Krzysztof Kozlowski <redacted>
Sent: 2023年9月28日 13:03
To: Ming Qian <ming.qian@nxp.com>; Mirela Rabulea (OSS)
[off-list ref]; robh+dt@kernel.org; shawnguo@kernel.org
Cc: krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org;
mchehab@kernel.org; hverkuil-cisco@xs4all.nl; s.hauer@pengutronix.de;
kernel@pengutronix.de; festevam@gmail.com; X.H. Bao
[off-list ref]; Eagle Zhou [off-list ref]; Tao Jiang
[off-list ref]; dl-linux-imx [off-list ref];
devicetree@vger.kernel.org; linux-media@vger.kernel.org; linux-
kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org
Subject: Re: [EXT] Re: [PATCH v4 1/2] arm64: dts: imx8-ss-img: Assign slot for
imx jpeg encoder/decoder

Caution: This is an external email. Please take care when clicking links or
opening attachments. When in doubt, report the message using the 'Report
this email' button


On 27/09/2023 11:19, Ming Qian wrote:

quoted

quoted

From: Krzysztof Kozlowski <redacted>
Sent: 2023年9月27日 16:11
To: Ming Qian <ming.qian@nxp.com>; Mirela Rabulea (OSS)
[off-list ref]; robh+dt@kernel.org;

shawnguo@kernel.org

quoted

quoted

Cc: krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org;
mchehab@kernel.org; hverkuil-cisco@xs4all.nl; s.hauer@pengutronix.de;
kernel@pengutronix.de; festevam@gmail.com; X.H. Bao
[off-list ref]; Eagle Zhou [off-list ref]; Tao Jiang
[off-list ref]; dl-linux-imx [off-list ref];
devicetree@vger.kernel.org; linux-media@vger.kernel.org; linux-
kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org
Subject: [EXT] Re: [PATCH v4 1/2] arm64: dts: imx8-ss-img: Assign
slot for imx jpeg encoder/decoder

Caution: This is an external email. Please take care when clicking
links or opening attachments. When in doubt, report the message using
the 'Report this email' button


On 26/09/2023 12:09, Ming Qian wrote:

quoted

There are total 4 slots available in the IP, and we only need to use
one slot in one os, assign a single slot for imx jpeg device node,
configure interrupt and power domain only for 1 slot, not for the all 4

slots.

quoted

quoted

DTS is independent of OS, so same DTS will be used by two OSes. This
patch is not correct in that matter. Explanation is not proper justification.

Hi Krzysztof,

I agree that DTS is independent of OS, otherwise we need to choose the slot

index by hard code in driver.

quoted

I think it's just the reason why we need this patch.
We have different platforms that use this IP, we need to configure the slot in

dts.

I still do not know what is the "slot". VM partitioning? Some pinmux
configuration?

Other platforms will use the same DTS, so the same slot and you are back at
the same problem... DTS should be the full description of the hardware, thus
removing interrupts is not "full description" anymore.

Hi Krzysztof,
    I have tried to explain the slot in the previous mail, although I'm not sure I made that clear. I think I need an example here. In our imx8q platform, we just want to assign slot 0 to linux, but in imx9 platform, we may want to assign slot 0 to linux, but slot 1 to a vm. So we don't want to enable power of slot 1 in linux.

Best regards,
Ming

quoted

Would you please give some guide about proper justification?

Describe architecture and then propose generic solution matching multiple
vendors and IP blocks, not something solving only this one problem.

Best regards,
Krzysztof

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel