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).
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;
+
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)
--
2.13.0