On Thu, 2017-07-06 at 18:49 +0200, Hans de Goede wrote: > 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). > Thanks, my comment below. For the quick fix I agree on this: Acked-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> By the way, do you need a shell script that allows to setup pin muxing via external CPLD? > Cc: stable@xxxxxxxxxxxxxxx > BugLink: 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> > --- > drivers/acpi/acpi_lpss.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c > index 10347e3d73ad..5bd58bd4ab05 100644 > --- a/drivers/acpi/acpi_lpss.c > +++ b/drivers/acpi/acpi_lpss.c > @@ -85,6 +85,7 @@ static const struct lpss_device_desc lpss_dma_desc = > { > }; > > 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; > + It would be nice to have a separate mapping between UID and lookup table. Though, for now it's only one case, perhaps we may do this later. > 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(struct > acpi_device *adev, > goto err_out; > } > > + pdata->adev = adev; > pdata->dev_desc = dev_desc; > > if (dev_desc->setup) -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy