Re: [PATCH v2] usb: gadget: fsl: Re-enable driver for ARM SoCs

On Fri, Jun 11, 2021 at 02:11:27AM +0000, Leo Li wrote:

quoted

-----Original Message-----
From: Joel Stanley <joel@jms.id.au>
Sent: Thursday, June 10, 2021 9:01 PM
To: Fabio Estevam <festevam@gmail.com>; Peter Chen
[off-list ref]; Arnd Bergmann [off-list ref]; Felipe Balbi
[off-list ref]; Shawn Guo [off-list ref]; Leo Li
[off-list ref]; dl-linux-imx [off-list ref]; Stephen
Rothwell [off-list ref]
Cc: linux-usb@vger.kernel.org; Linux ARM <linux-arm-
kernel@lists.infradead.org>
Subject: Re: [PATCH v2] usb: gadget: fsl: Re-enable driver for ARM SoCs

On Thu, 10 Jun 2021 at 03:50, Joel Stanley [off-list ref] wrote:

quoted

The commit a390bef7db1f ("usb: gadget: fsl_mxc_udc: Remove the
driver") dropped the ARCH_MXC dependency from USB_FSL_USB2,

leaving it

quoted

depending solely on FSL_SOC.

FSL_SOC is powerpc only; it was briefly available on ARM in 2014 but
was removed by commit cfd074ad8600 ("ARM: imx: temporarily remove
CONFIG_SOC_FSL from LS1021A"). Therefore the driver can no longer be
enabled on ARM platforms.

This appears to be a mistake as arm64's ARCH_LAYERSCAPE and arm32
SOC_LS1021A SoCs use this symbol. It's enabled in these defconfigs:

arch/arm/configs/imx_v6_v7_defconfig:CONFIG_USB_FSL_USB2=y
arch/arm/configs/multi_v7_defconfig:CONFIG_USB_FSL_USB2=y
arch/powerpc/configs/mgcoge_defconfig:CONFIG_USB_FSL_USB2=y
arch/powerpc/configs/mpc512x_defconfig:CONFIG_USB_FSL_USB2=y

To fix, expand the dependencies so USB_FSL_USB2 can be enabled on the
ARM platforms, and with COMPILE_TEST.

This didn't work out, as there's some missing clock initialisation calls that were
removed when fsl_mxc_udc was deleted:

arm-linux-gnueabi-ld: drivers/usb/gadget/udc/fsl_udc_core.o: in function
`fsl_udc_remove':
fsl_udc_core.c:(.text+0xc88): undefined reference to `fsl_udc_clk_release'
arm-linux-gnueabi-ld: drivers/usb/gadget/udc/fsl_udc_core.o: in function
`fsl_udc_probe':
fsl_udc_core.c:(.text+0x1c44): undefined reference to `fsl_udc_clk_init'
arm-linux-gnueabi-ld: fsl_udc_core.c:(.text+0x1dcc): undefined reference to
`fsl_udc_clk_finalize'
arm-linux-gnueabi-ld: fsl_udc_core.c:(.text+0x1fe8): undefined reference to
`fsl_udc_clk_release'

We could add them back, but it's not clear if this driver is still maintained. I'm
looking to the NXP people for input here.

Adding Ran Wang to the loop.  I think we will maintain the driver to keep the legacy platforms working but will not add new users of this driver.

Now reverted in my tree.

thanks,

greg k-h

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