2021-12-06 11:43:37

by Stephan Gerhold

[permalink] [raw]
Subject: [PATCH] soc: imx: Register SoC device only on i.MX boards

At the moment, using the ARM32 multi_v7_defconfig always results in two
SoCs being exposed in sysfs. This is wrong, as far as I'm aware the
Qualcomm DragonBoard 410c does not actually make use of a i.MX SoC. :)

qcom-db410c:/sys/devices/soc0$ grep . *
family:Freescale i.MX
machine:Qualcomm Technologies, Inc. APQ 8016 SBC
revision:0.0
serial_number:0000000000000000
soc_id:Unknown

qcom-db410c:/sys/devices/soc1$ grep . *
family:Snapdragon
machine:APQ8016
...

This happens because imx_soc_device_init() registers the soc device
unconditionally, even when running on devices that do not make use of i.MX.
Arnd already reported this more than a year ago and even suggested a fix
similar to this commit, but for some reason it was never submitted.

Fix it by checking if the "__mxc_cpu_type" variable was actually
initialized by earlier platform code. On devices without i.MX it will
simply stay 0.

Cc: Peng Fan <[email protected]>
Fixes: d2199b34871b ("ARM: imx: use device_initcall for imx_soc_device_init")
Reported-by: Arnd Bergmann <[email protected]>
Link: https://lore.kernel.org/r/CAK8P3a0hxO1TmK6oOMQ70AHSWJnP_CAq57YMOutrxkSYNjFeuw@mail.gmail.com/
Signed-off-by: Stephan Gerhold <[email protected]>
---
drivers/soc/imx/soc-imx.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/soc/imx/soc-imx.c b/drivers/soc/imx/soc-imx.c
index ac6d856ba228..77bc12039c3d 100644
--- a/drivers/soc/imx/soc-imx.c
+++ b/drivers/soc/imx/soc-imx.c
@@ -36,6 +36,10 @@ static int __init imx_soc_device_init(void)
int ret;
int i;

+ /* Return early if this is running on devices with different SoCs */
+ if (!__mxc_cpu_type)
+ return 0;
+
if (of_machine_is_compatible("fsl,ls1021a"))
return 0;

--
2.34.1



2021-12-06 11:58:31

by Fabio Estevam

[permalink] [raw]
Subject: Re: [PATCH] soc: imx: Register SoC device only on i.MX boards

On Mon, Dec 6, 2021 at 8:40 AM Stephan Gerhold <[email protected]> wrote:
>
> At the moment, using the ARM32 multi_v7_defconfig always results in two
> SoCs being exposed in sysfs. This is wrong, as far as I'm aware the
> Qualcomm DragonBoard 410c does not actually make use of a i.MX SoC. :)
>
> qcom-db410c:/sys/devices/soc0$ grep . *
> family:Freescale i.MX
> machine:Qualcomm Technologies, Inc. APQ 8016 SBC
> revision:0.0
> serial_number:0000000000000000
> soc_id:Unknown
>
> qcom-db410c:/sys/devices/soc1$ grep . *
> family:Snapdragon
> machine:APQ8016
> ...
>
> This happens because imx_soc_device_init() registers the soc device
> unconditionally, even when running on devices that do not make use of i.MX.
> Arnd already reported this more than a year ago and even suggested a fix
> similar to this commit, but for some reason it was never submitted.
>
> Fix it by checking if the "__mxc_cpu_type" variable was actually
> initialized by earlier platform code. On devices without i.MX it will
> simply stay 0.
>
> Cc: Peng Fan <[email protected]>
> Fixes: d2199b34871b ("ARM: imx: use device_initcall for imx_soc_device_init")
> Reported-by: Arnd Bergmann <[email protected]>
> Link: https://lore.kernel.org/r/CAK8P3a0hxO1TmK6oOMQ70AHSWJnP_CAq57YMOutrxkSYNjFeuw@mail.gmail.com/
> Signed-off-by: Stephan Gerhold <[email protected]>

Reviewed-by: Fabio Estevam <[email protected]>

2021-12-06 12:23:09

by Peng Fan

[permalink] [raw]
Subject: RE: [PATCH] soc: imx: Register SoC device only on i.MX boards

> Subject: [PATCH] soc: imx: Register SoC device only on i.MX boards
>
> At the moment, using the ARM32 multi_v7_defconfig always results in two
> SoCs being exposed in sysfs. This is wrong, as far as I'm aware the Qualcomm
> DragonBoard 410c does not actually make use of a i.MX SoC. :)
>
> qcom-db410c:/sys/devices/soc0$ grep . *
> family:Freescale i.MX
> machine:Qualcomm Technologies, Inc. APQ 8016 SBC
> revision:0.0
> serial_number:0000000000000000
> soc_id:Unknown
>
> qcom-db410c:/sys/devices/soc1$ grep . *
> family:Snapdragon
> machine:APQ8016
> ...
>
> This happens because imx_soc_device_init() registers the soc device
> unconditionally, even when running on devices that do not make use of i.MX.
> Arnd already reported this more than a year ago and even suggested a fix
> similar to this commit, but for some reason it was never submitted.
>
> Fix it by checking if the "__mxc_cpu_type" variable was actually initialized by
> earlier platform code. On devices without i.MX it will simply stay 0.
>
> Cc: Peng Fan <[email protected]>
> Fixes: d2199b34871b ("ARM: imx: use device_initcall for
> imx_soc_device_init")
> Reported-by: Arnd Bergmann <[email protected]>
> Link:
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.ke
> rnel.org%2Fr%2FCAK8P3a0hxO1TmK6oOMQ70AHSWJnP_CAq57YMOutrxkSY
> NjFeuw%40mail.gmail.com%2F&amp;data=04%7C01%7Cpeng.fan%40nxp.co
> m%7Cba6334562b49404f88b708d9b8ad36b5%7C686ea1d3bc2b4c6fa92cd9
> 9c5c301635%7C0%7C0%7C637743876348146819%7CUnknown%7CTWFpbG
> Zsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6
> Mn0%3D%7C3000&amp;sdata=mAeB%2FvXO4cUbcPPLBH14LkDzxMz2w5SLj
> iNEZhjgFuU%3D&amp;reserved=0
> Signed-off-by: Stephan Gerhold <[email protected]>

Reviewed-by: Peng Fan <[email protected]>

> ---
> drivers/soc/imx/soc-imx.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/soc/imx/soc-imx.c b/drivers/soc/imx/soc-imx.c index
> ac6d856ba228..77bc12039c3d 100644
> --- a/drivers/soc/imx/soc-imx.c
> +++ b/drivers/soc/imx/soc-imx.c
> @@ -36,6 +36,10 @@ static int __init imx_soc_device_init(void)
> int ret;
> int i;
>
> + /* Return early if this is running on devices with different SoCs */
> + if (!__mxc_cpu_type)
> + return 0;
> +
> if (of_machine_is_compatible("fsl,ls1021a"))
> return 0;
>
> --
> 2.34.1


2021-12-08 12:30:38

by Shawn Guo

[permalink] [raw]
Subject: Re: [PATCH] soc: imx: Register SoC device only on i.MX boards

On Mon, Dec 06, 2021 at 12:38:28PM +0100, Stephan Gerhold wrote:
> At the moment, using the ARM32 multi_v7_defconfig always results in two
> SoCs being exposed in sysfs. This is wrong, as far as I'm aware the
> Qualcomm DragonBoard 410c does not actually make use of a i.MX SoC. :)
>
> qcom-db410c:/sys/devices/soc0$ grep . *
> family:Freescale i.MX
> machine:Qualcomm Technologies, Inc. APQ 8016 SBC
> revision:0.0
> serial_number:0000000000000000
> soc_id:Unknown
>
> qcom-db410c:/sys/devices/soc1$ grep . *
> family:Snapdragon
> machine:APQ8016
> ...
>
> This happens because imx_soc_device_init() registers the soc device
> unconditionally, even when running on devices that do not make use of i.MX.
> Arnd already reported this more than a year ago and even suggested a fix
> similar to this commit, but for some reason it was never submitted.
>
> Fix it by checking if the "__mxc_cpu_type" variable was actually
> initialized by earlier platform code. On devices without i.MX it will
> simply stay 0.
>
> Cc: Peng Fan <[email protected]>
> Fixes: d2199b34871b ("ARM: imx: use device_initcall for imx_soc_device_init")
> Reported-by: Arnd Bergmann <[email protected]>
> Link: https://lore.kernel.org/r/CAK8P3a0hxO1TmK6oOMQ70AHSWJnP_CAq57YMOutrxkSYNjFeuw@mail.gmail.com/
> Signed-off-by: Stephan Gerhold <[email protected]>

Applied, thanks!