Registers of DSPI should not be accessed before enabling its clock. On
Toradex Colibri VF50 on Iris carrier board this could be seen during
bootup as imprecise abort:
Unhandled fault: imprecise external abort (0x1c06) at 0x00000000
Internal error: : 1c06 [#1] ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.14.39-dirty #97
Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
Backtrace:
[<804166a8>] (regmap_write) from [<80466b5c>] (dspi_probe+0x1f0/0x8dc)
[<8046696c>] (dspi_probe) from [<8040107c>] (platform_drv_probe+0x54/0xb8)
[<80401028>] (platform_drv_probe) from [<803ff53c>] (driver_probe_device+0x280/0x2f8)
[<803ff2bc>] (driver_probe_device) from [<803ff674>] (__driver_attach+0xc0/0xc4)
[<803ff5b4>] (__driver_attach) from [<803fd818>] (bus_for_each_dev+0x70/0xa4)
[<803fd7a8>] (bus_for_each_dev) from [<803fee74>] (driver_attach+0x24/0x28)
[<803fee50>] (driver_attach) from [<803fe980>] (bus_add_driver+0x1a0/0x218)
[<803fe7e0>] (bus_add_driver) from [<803fffe8>] (driver_register+0x80/0x100)
[<803fff68>] (driver_register) from [<80400fdc>] (__platform_driver_register+0x48/0x50)
[<80400f94>] (__platform_driver_register) from [<8091cf7c>] (fsl_dspi_driver_init+0x1c/0x20)
[<8091cf60>] (fsl_dspi_driver_init) from [<8010195c>] (do_one_initcall+0x4c/0x174)
[<80101910>] (do_one_initcall) from [<80900e8c>] (kernel_init_freeable+0x144/0x1d8)
[<80900d48>] (kernel_init_freeable) from [<805ff6a8>] (kernel_init+0x10/0x114)
[<805ff698>] (kernel_init) from [<80107be8>] (ret_from_fork+0x14/0x2c)
Cc: <stable@vger.kernel.org>
Fixes: 5ee67b587a2b ("spi: dspi: clear SPI_SR before enable interrupt")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
d8ffee2f55