4.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hans de Goede <hdegoede@xxxxxxxxxx> commit dd242a080d178c36442a0bb28b6acf6f126d0569 upstream. At least on the UP board SBC both PWMs are enabled leading to us trying to add the same pwm_lookup twice, which leads to the following: [ 0.902224] list_add double add: new=ffffffffb8efd400, prev=ffffffffb8efd400, next=ffffffffb8eeede0. [ 0.912466] ------------[ cut here ]------------ [ 0.917624] kernel BUG at lib/list_debug.c:31! [ 0.922588] invalid opcode: 0000 [#1] SMP ... [ 1.027450] Call Trace: [ 1.030185] pwm_add_table+0x4c/0x90 [ 1.034181] bsw_pwm_setup+0x1a/0x20 [ 1.038175] acpi_lpss_create_device+0xfe/0x420 ... This commit fixes this by only calling pwm_add_table() for the first PWM controller (which is the one used for the backlight). Link: https://bugzilla.redhat.com/show_bug.cgi?id=1458599 Fixes: bf7696a12071 (acpi: lpss: call pwm_add_table() for BSW...) Fixes: 04434ab5120a (ACPI / LPSS: Call pwm_add_table() for Bay Trail...) Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Acked-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/acpi/acpi_lpss.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -85,6 +85,7 @@ static const struct lpss_device_desc lps }; struct lpss_private_data { + struct acpi_device *adev; void __iomem *mmio_base; resource_size_t mmio_size; unsigned int fixed_clk_rate; @@ -155,6 +156,12 @@ static struct pwm_lookup byt_pwm_lookup[ static void byt_pwm_setup(struct lpss_private_data *pdata) { + struct acpi_device *adev = pdata->adev; + + /* Only call pwm_add_table for the first PWM controller */ + if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1")) + return; + if (!acpi_dev_present("INT33FD", NULL, -1)) pwm_add_table(byt_pwm_lookup, ARRAY_SIZE(byt_pwm_lookup)); } @@ -180,6 +187,12 @@ static struct pwm_lookup bsw_pwm_lookup[ static void bsw_pwm_setup(struct lpss_private_data *pdata) { + struct acpi_device *adev = pdata->adev; + + /* Only call pwm_add_table for the first PWM controller */ + if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1")) + return; + pwm_add_table(bsw_pwm_lookup, ARRAY_SIZE(bsw_pwm_lookup)); } @@ -456,6 +469,7 @@ static int acpi_lpss_create_device(struc goto err_out; } + pdata->adev = adev; pdata->dev_desc = dev_desc; if (dev_desc->setup)