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Sender: Guenter Roeck <groeck7@gmail.com>
Date:   Tue, 30 Mar 2021 08:42:23 -0700
From:   Guenter Roeck <linux@roeck-us.net>
To:     Tudor Ambarus <tudor.ambarus@microchip.com>
Cc:     corbet@lwn.net, gregkh@linuxfoundation.org, rafael@kernel.org,
        khilman@kernel.org, ulf.hansson@linaro.org, len.brown@intel.com,
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        maz@kernel.org, tglx@linutronix.de, saravanak@google.com,
        nicolas.ferre@microchip.com, claudiu.beznea@microchip.com,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-pm@vger.kernel.org, linux-clk@vger.kernel.org,
        devicetree@vger.kernel.org, linux-acpi@vger.kernel.org,
        m.szyprowski@samsung.com, geert@linux-m68k.org,
        kernel-team@android.com
Subject: Re: [PATCH] clk: Mark fwnodes when their clock provider is added
Message-ID: <20210330154222.GA5411@roeck-us.net>
References: <20210205222644.2357303-9-saravanak@google.com>
 <20210210114435.122242-1-tudor.ambarus@microchip.com>
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In-Reply-To: <20210210114435.122242-1-tudor.ambarus@microchip.com>
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On Wed, Feb 10, 2021 at 01:44:34PM +0200, Tudor Ambarus wrote:
> This is a follow-up for:
> commit 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is added/removed")
> 
> The above commit updated the deprecated of_clk_add_provider(),
> but missed to update the preferred of_clk_add_hw_provider().
> Update it now.
> 
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> Reviewed-by: Saravana Kannan <saravanak@google.com>
> ---
>  drivers/clk/clk.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 27ff90eacb1f..9370e4dfecae 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -4594,6 +4594,8 @@ int of_clk_add_hw_provider(struct device_node *np,
>  	if (ret < 0)
>  		of_clk_del_provider(np);
>  
> +	fwnode_dev_initialized(&np->fwnode, true);
> +

This causes a crash when booting raspi2 images in qemu.

[   22.123618] Unable to handle kernel NULL pointer dereference at virtual address 00000028
[   22.123830] pgd = (ptrval)
[   22.123992] [00000028] *pgd=00000000
[   22.124579] Internal error: Oops: 5 [#1] SMP ARM
...
[   22.141624] [<c0a2f4d8>] (of_clk_add_hw_provider) from [<c0a2f54c>] (devm_of_clk_add_hw_provider+0x48/0x80)
[   22.141819] [<c0a2f54c>] (devm_of_clk_add_hw_provider) from [<c0a43ad8>] (raspberrypi_clk_probe+0x25c/0x384)
[   22.141976] [<c0a43ad8>] (raspberrypi_clk_probe) from [<c0c18da0>] (platform_probe+0x5c/0xb8)
[   22.142114] [<c0c18da0>] (platform_probe) from [<c0c16654>] (really_probe+0xf0/0x39c)
[   22.142246] [<c0c16654>] (really_probe) from [<c0c16968>] (driver_probe_device+0x68/0xc0)
[   22.142377] [<c0c16968>] (driver_probe_device) from [<c0c14834>] (bus_for_each_drv+0x84/0xc8)...

np can (and will) be NULL here. See of_clk_set_defaults().

Guenter

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Bisect log:

# bad: [9d49ed9ca93b8c564033c1d6808017bc9052b5db] Add linux-next specific files for 20210329
# good: [0d02ec6b3136c73c09e7859f0d0e4e2c4c07b49b] Linux 5.12-rc4
git bisect start 'HEAD' 'v5.12-rc4'
# good: [4b15c5b50e5ec7f2d80275d5a150807b7b9a0a0c] Merge remote-tracking branch 'crypto/master'
git bisect good 4b15c5b50e5ec7f2d80275d5a150807b7b9a0a0c
# good: [c92ad2dfc1a3bc31afc3d41af82c38accf2c3783] Merge remote-tracking branch 'ftrace/for-next'
git bisect good c92ad2dfc1a3bc31afc3d41af82c38accf2c3783
# bad: [103c8000962c33e274244a02a0383d20fab734c9] Merge remote-tracking branch 'staging/staging-next'
git bisect bad 103c8000962c33e274244a02a0383d20fab734c9
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git bisect bad 05ee9b17ef7af7d47395caa48db55d0e2dae64a2
# good: [bd91c862df59c0290c8a2e2ee6467c0ed5fb6432] Merge remote-tracking branch 'workqueues/for-next'
git bisect good bd91c862df59c0290c8a2e2ee6467c0ed5fb6432
# good: [24327c478b2fc17a01b21a4721f35f22a51fe12b] usb: mtu3: drop CONFIG_OF
git bisect good 24327c478b2fc17a01b21a4721f35f22a51fe12b
# bad: [04c49226ac79b3e5bd0f89da69a64ba2e0cccb91] Merge remote-tracking branch 'usb-serial/usb-next'
git bisect bad 04c49226ac79b3e5bd0f89da69a64ba2e0cccb91
# good: [21a292d73a6e69f31c57d36288482c40b355daf0] Merge remote-tracking branch 'drivers-x86/for-next'
git bisect good 21a292d73a6e69f31c57d36288482c40b355daf0
# bad: [b6688015151857ed3f61fa2344c4b220bc9dc4d7] regulator: qcom_spmi-regulator: Clean-up by using managed work init
git bisect bad b6688015151857ed3f61fa2344c4b220bc9dc4d7
# good: [ea718c699055c8566eb64432388a04974c43b2ea] Revert "Revert "driver core: Set fw_devlink=on by default""
git bisect good ea718c699055c8566eb64432388a04974c43b2ea
# bad: [0341ce5443949588e93581b49b934cdde2befbf8] workqueue: Add resource managed version of delayed work init
git bisect bad 0341ce5443949588e93581b49b934cdde2befbf8
# bad: [0b8bf06f67191e6a3184802a690d3f521c6d7e78] device property: Sync descriptions of swnode array and group APIs
git bisect bad 0b8bf06f67191e6a3184802a690d3f521c6d7e78
# bad: [6579c8d97ad7fc5671ee60234f3b8388abee5f77] clk: Mark fwnodes when their clock provider is added
git bisect bad 6579c8d97ad7fc5671ee60234f3b8388abee5f77
# first bad commit: [6579c8d97ad7fc5671ee60234f3b8388abee5f77] clk: Mark fwnodes when their clock provider is added