Message-ID: <aIh8JPTv9Z5lphRQ@sultan-box>
Date: Tue, 29 Jul 2025 00:45:40 -0700
From: Sultan Alsawaf <sultan@...neltoast.com>
To: "Du, Bin" <bin.du@....com>
Cc: mchehab@...nel.org, hverkuil@...all.nl,
	laurent.pinchart+renesas@...asonboard.com,
	bryan.odonoghue@...aro.org, sakari.ailus@...ux.intel.com,
	prabhakar.mahadev-lad.rj@...renesas.com,
	linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
	pratap.nirujogi@....com, benjamin.chan@....com, king.li@....com,
	gjorgji.rosikopulos@....com, Phil.Jawich@....com,
	Dominic.Antony@....com
Subject: Re: [PATCH v2 0/8] Add AMD ISP4 driver

On Tue, Jul 29, 2025 at 12:42:16AM -0700, Sultan Alsawaf wrote:
> On Tue, Jul 29, 2025 at 11:32:23AM +0800, Du, Bin wrote:
> > Thanks Sultan, please see my comments
> > 
> > On 7/27/2025 6:31 AM, Sultan Alsawaf wrote:
> > > On Fri, Jul 25, 2025 at 06:22:03PM +0800, Du, Bin wrote:
> > > > > I have the Ryzen AI MAX+ 395 SKU of the HP ZBook Ultra G1a 14.
> > > > > 
> > > > > I cannot for the life of me get the webcam working under Linux. The webcam works
> > > > > under Windows so it's not a hardware issue.
> > > > > 
> > > > > With this patchset and all of the patches you link here applied to 6.15, I get
> > > > > the following errors:
> > > > >     [   11.970038] amd_isp_i2c_designware amd_isp_i2c_designware: Unknown Synopsys component type: 0xffffffff
> > > > >     [   11.973162] amd_isp_i2c_designware amd_isp_i2c_designware: error -19: i2c_dw_probe failed
> > > > > 
> > > > > With the old ispkernel code from February [1] applied on 6.15, the webcam
> > > > > indicator LED lights up but there's no image. I see these messages at boot:
> > > > >     [    9.449005] amd_isp_capture amd_isp_capture.1.auto: amdgpu: AMD ISP v4l2 device registered
> > > > >     [    9.489005] amd_isp_i2c_designware amd_isp_i2c_designware.2.auto: The OV05 sensor device is added to the ISP I2C bus
> > > > >     [    9.529012] amd_isp_i2c_designware amd_isp_i2c_designware.2.auto: timeout while trying to abort current transfer
> > > > >     [    9.554046] amd_isp_i2c_designware amd_isp_i2c_designware.2.auto: timeout in disabling adapter
> > > > >     [    9.554174] amd_isp_i2c_designware amd_isp_i2c_designware.2.auto: timeout while trying to abort current transfer
> > > > >     [    9.580022] amd_isp_i2c_designware amd_isp_i2c_designware.2.auto: timeout in disabling adapter
> > > > > 
> > > > > And then the kernel crashes due to the same use-after-free issues I pointed out
> > > > > in my other email [2].
> > > > > 
> > > > > Any idea what's going on?
> > > > > 
> > > > > [1] https://github.com/amd/Linux_ISP_Kernel/commit/c6d42584fbd0aa42cc91ecf16dc5c4f3dfea0bb4
> > > > > [2] https://lore.kernel.org/r/aIEiJL83pOYO8lUJ@sultan-box
> > > > Hi Sultan,
> > > > 
> > > > [1] is for kernel 6.8, believe it can't be applied to 6.15. We didn't verify
> > > > on 6.15 but we are really glad to help, would you please provide some info,
> > > > 1. Suppose you are using Ubuntu, right? What's the version?
> > > > 2. 6.15, do you mean https://github.com/torvalds/linux/tree/v6.15 ?
> > > > 
> > > > After your confirmation, we'll see what we can do to enable your camera
> > > > quickly and easily
> > > > 
> > > > Regards,
> > > > Bin
> > > 
> > > Thank you, Bin!
> > > 
> > > 1. I'm using Arch Linux with the ISP4-patched libcamera [1].
> > > 2. Yes, here is my kernel source [2].
> > > 
> > > I have some more findings:
> > > 
> > > Currently, the first blocking issue is that the I2C adapter fails to initialize.
> > > This is because the ISP tile isn't powered on.
> > > 
> > > I noticed that in the old version of amd_isp_i2c_designware [3], there were
> > > calls to isp_power_set(), which is available in the old ISP4 sources [4].
> > > Without isp_power_set(), the I2C adapter always fails to initialize for me.
> > > 
> > > How is the ISP tile supposed to get powered on in the current ISP4 code?
> > > 
> > You are correct, yes, i believe the I2C adapter failure is caused by ISP not
> > being powered up. Currently in latest code, isp_power_set is no longer
> > available, instead, we implemented genPD for ISP in amdgpu
> > https://lore.kernel.org/all/20250618221923.3944751-1-pratap.nirujogi@amd.com/
> > Both amd_isp_i2c and amd_isp_capture are in the power domain and use the
> > standard runtime PM API to do the power control
> 
> Thanks for that link, I found it along with another patch on the list to make
> the fwnode work ("drm/amd/amdgpu: Initialize swnode for ISP MFD device").
> 
> > > Also, I noticed that the driver init ordering matters between all of the drivers
> > > needed for the ISP4 camera. In particular, amd_isp_i2c_designware and amd_isp4
> > > must be initialized before amd_capture, otherwise amd_capture will fail to find
> > > the fwnode properties for the OV05C10 device attached to the I2C bus.
> > > 
> > > But there is no driver init ordering enforced, which also caused some issues for
> > > me until I figured it out. Maybe probe deferral (-EPROBE_DEFER) should be used
> > > to ensure each driver waits for its dependencies to init first?
> > > 
> > amd_isp_capture only has dependency on amd_isp4 which is the ACPI platform
> > driver, it is init before amd_isp_catpure.
> > Do you see in your side the amd_capture probe failure caused by failing to
> > read fwnode properties? If that's the case please help to check if amd_isp4
> > is loaded successfully
> 
> I got much further now: there aren't any driver initialization errors, but when
> I open the camera, there's no image. The camera LED turns on so it's active.
> 
> And then shortly afterwards, amdgpu dies and the entire system freezes.
> 
> I've attached my full dmesg, please let me know what you think. Thanks!

I almost forgot, here is my current kernel tree:
https://github.com/kerneltoast/kernel_x86_laptop/tree/v6.16-sultan-isp4

Sultan

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