Fix the following BUG by disabling locking for the cr_regmap config.
BUG: sleeping function called from invalid context at drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c:85
in_atomic(): 1, irqs_disabled(): 128, pid: 60, name: kworker/3:1
[snip]
Workqueue: events deferred_probe_work_func
Call trace:
dump_backtrace+0x0/0x190
show_stack+0x14/0x20
dump_stack+0x90/0xb4
___might_sleep+0xec/0x110
__might_sleep+0x50/0x88
phy_g12a_usb3_pcie_cr_bus_addr.isra.0+0x80/0x1a8
phy_g12a_usb3_pcie_cr_bus_read+0x34/0x1d8
_regmap_read+0x60/0xe0
_regmap_update_bits+0xc4/0x110
regmap_update_bits_base+0x60/0x90
phy_g12a_usb3_pcie_init+0xdc/0x210
phy_init+0x74/0xd0
dwc3_meson_g12a_probe+0x2cc/0x4d0
platform_drv_probe+0x50/0xa0
really_probe+0x20c/0x3b8
driver_probe_device+0x68/0x150
__device_attach_driver+0xa8/0x170
bus_for_each_drv+0x64/0xc8
__device_attach+0xd8/0x158
device_initial_probe+0x10/0x18
bus_probe_device+0x90/0x98
deferred_probe_work_func+0x94/0xe8
process_one_work+0x1e0/0x338
worker_thread+0x230/0x458
kthread+0x134/0x138
ret_from_fork+0x10/0x1c
Fixes: 36077e16c050 ("phy: amlogic: Add Amlogic G12A USB3 + PCIE Combo PHY Driver")
Signed-off-by: Neil Armstrong <[email protected]>
---
drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c b/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
index 6233a7979a93..ac322d643c7a 100644
--- a/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
+++ b/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
@@ -188,7 +188,7 @@ static const struct regmap_config phy_g12a_usb3_pcie_cr_regmap_conf = {
.reg_read = phy_g12a_usb3_pcie_cr_bus_read,
.reg_write = phy_g12a_usb3_pcie_cr_bus_write,
.max_register = 0xffff,
- .fast_io = true,
+ .disable_locking = true,
};
static int phy_g12a_usb3_init(struct phy *phy)
--
2.21.0
Hi,
On 31/05/19 4:01 PM, Neil Armstrong wrote:
> Fix the following BUG by disabling locking for the cr_regmap config.
What caused the BUG in the first place? The commit log needs more details or
else this looks like a workaround to mask a BUG.
Thanks
Kishon
>
> BUG: sleeping function called from invalid context at drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c:85
> in_atomic(): 1, irqs_disabled(): 128, pid: 60, name: kworker/3:1
> [snip]
> Workqueue: events deferred_probe_work_func
> Call trace:
> dump_backtrace+0x0/0x190
> show_stack+0x14/0x20
> dump_stack+0x90/0xb4
> ___might_sleep+0xec/0x110
> __might_sleep+0x50/0x88
> phy_g12a_usb3_pcie_cr_bus_addr.isra.0+0x80/0x1a8
> phy_g12a_usb3_pcie_cr_bus_read+0x34/0x1d8
> _regmap_read+0x60/0xe0
> _regmap_update_bits+0xc4/0x110
> regmap_update_bits_base+0x60/0x90
> phy_g12a_usb3_pcie_init+0xdc/0x210
> phy_init+0x74/0xd0
> dwc3_meson_g12a_probe+0x2cc/0x4d0
> platform_drv_probe+0x50/0xa0
> really_probe+0x20c/0x3b8
> driver_probe_device+0x68/0x150
> __device_attach_driver+0xa8/0x170
> bus_for_each_drv+0x64/0xc8
> __device_attach+0xd8/0x158
> device_initial_probe+0x10/0x18
> bus_probe_device+0x90/0x98
> deferred_probe_work_func+0x94/0xe8
> process_one_work+0x1e0/0x338
> worker_thread+0x230/0x458
> kthread+0x134/0x138
> ret_from_fork+0x10/0x1c
>
> Fixes: 36077e16c050 ("phy: amlogic: Add Amlogic G12A USB3 + PCIE Combo PHY Driver")
> Signed-off-by: Neil Armstrong <[email protected]>
> ---
> drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c b/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
> index 6233a7979a93..ac322d643c7a 100644
> --- a/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
> +++ b/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
> @@ -188,7 +188,7 @@ static const struct regmap_config phy_g12a_usb3_pcie_cr_regmap_conf = {
> .reg_read = phy_g12a_usb3_pcie_cr_bus_read,
> .reg_write = phy_g12a_usb3_pcie_cr_bus_write,
> .max_register = 0xffff,
> - .fast_io = true,
> + .disable_locking = true,
> };
>
> static int phy_g12a_usb3_init(struct phy *phy)
>
On 31/05/2019 12:35, Kishon Vijay Abraham I wrote:
> Hi,
>
> On 31/05/19 4:01 PM, Neil Armstrong wrote:
>> Fix the following BUG by disabling locking for the cr_regmap config.
>
> What caused the BUG in the first place? The commit log needs more details or
> else this looks like a workaround to mask a BUG.
I thought it was pretty explicit, phy_g12a_usb3_pcie_cr_bus_read() sleeps
with regmap_read_poll_timeout() while ran in spinlock_irq, caused by regmap fast_io = true
Locking is not needed in our case, this regmap is only used by the PHY init() callback.
Should I send a v2 with such explanation ?
Neil
>
> Thanks
> Kishon
>
>>
>> BUG: sleeping function called from invalid context at drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c:85
>> in_atomic(): 1, irqs_disabled(): 128, pid: 60, name: kworker/3:1
>> [snip]
>> Workqueue: events deferred_probe_work_func
>> Call trace:
>> dump_backtrace+0x0/0x190
>> show_stack+0x14/0x20
>> dump_stack+0x90/0xb4
>> ___might_sleep+0xec/0x110
>> __might_sleep+0x50/0x88
>> phy_g12a_usb3_pcie_cr_bus_addr.isra.0+0x80/0x1a8
>> phy_g12a_usb3_pcie_cr_bus_read+0x34/0x1d8
>> _regmap_read+0x60/0xe0
>> _regmap_update_bits+0xc4/0x110
>> regmap_update_bits_base+0x60/0x90
>> phy_g12a_usb3_pcie_init+0xdc/0x210
>> phy_init+0x74/0xd0
>> dwc3_meson_g12a_probe+0x2cc/0x4d0
>> platform_drv_probe+0x50/0xa0
>> really_probe+0x20c/0x3b8
>> driver_probe_device+0x68/0x150
>> __device_attach_driver+0xa8/0x170
>> bus_for_each_drv+0x64/0xc8
>> __device_attach+0xd8/0x158
>> device_initial_probe+0x10/0x18
>> bus_probe_device+0x90/0x98
>> deferred_probe_work_func+0x94/0xe8
>> process_one_work+0x1e0/0x338
>> worker_thread+0x230/0x458
>> kthread+0x134/0x138
>> ret_from_fork+0x10/0x1c
>>
>> Fixes: 36077e16c050 ("phy: amlogic: Add Amlogic G12A USB3 + PCIE Combo PHY Driver")
>> Signed-off-by: Neil Armstrong <[email protected]>
>> ---
>> drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c b/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
>> index 6233a7979a93..ac322d643c7a 100644
>> --- a/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
>> +++ b/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
>> @@ -188,7 +188,7 @@ static const struct regmap_config phy_g12a_usb3_pcie_cr_regmap_conf = {
>> .reg_read = phy_g12a_usb3_pcie_cr_bus_read,
>> .reg_write = phy_g12a_usb3_pcie_cr_bus_write,
>> .max_register = 0xffff,
>> - .fast_io = true,
>> + .disable_locking = true,
>> };
>>
>> static int phy_g12a_usb3_init(struct phy *phy)
>>
On 31/05/19 7:52 PM, Neil Armstrong wrote:
> On 31/05/2019 12:35, Kishon Vijay Abraham I wrote:
>> Hi,
>>
>> On 31/05/19 4:01 PM, Neil Armstrong wrote:
>>> Fix the following BUG by disabling locking for the cr_regmap config.
>>
>> What caused the BUG in the first place? The commit log needs more details or
>> else this looks like a workaround to mask a BUG.
>
> I thought it was pretty explicit, phy_g12a_usb3_pcie_cr_bus_read() sleeps
> with regmap_read_poll_timeout() while ran in spinlock_irq, caused by regmap fast_io = true
>
> Locking is not needed in our case, this regmap is only used by the PHY init() callback.
>
> Should I send a v2 with such explanation ?
yes, should atleast mention locking is not needed here.
-Kishon
>
> Neil
>
>>
>> Thanks
>> Kishon
>>
>>>
>>> BUG: sleeping function called from invalid context at drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c:85
>>> in_atomic(): 1, irqs_disabled(): 128, pid: 60, name: kworker/3:1
>>> [snip]
>>> Workqueue: events deferred_probe_work_func
>>> Call trace:
>>> dump_backtrace+0x0/0x190
>>> show_stack+0x14/0x20
>>> dump_stack+0x90/0xb4
>>> ___might_sleep+0xec/0x110
>>> __might_sleep+0x50/0x88
>>> phy_g12a_usb3_pcie_cr_bus_addr.isra.0+0x80/0x1a8
>>> phy_g12a_usb3_pcie_cr_bus_read+0x34/0x1d8
>>> _regmap_read+0x60/0xe0
>>> _regmap_update_bits+0xc4/0x110
>>> regmap_update_bits_base+0x60/0x90
>>> phy_g12a_usb3_pcie_init+0xdc/0x210
>>> phy_init+0x74/0xd0
>>> dwc3_meson_g12a_probe+0x2cc/0x4d0
>>> platform_drv_probe+0x50/0xa0
>>> really_probe+0x20c/0x3b8
>>> driver_probe_device+0x68/0x150
>>> __device_attach_driver+0xa8/0x170
>>> bus_for_each_drv+0x64/0xc8
>>> __device_attach+0xd8/0x158
>>> device_initial_probe+0x10/0x18
>>> bus_probe_device+0x90/0x98
>>> deferred_probe_work_func+0x94/0xe8
>>> process_one_work+0x1e0/0x338
>>> worker_thread+0x230/0x458
>>> kthread+0x134/0x138
>>> ret_from_fork+0x10/0x1c
>>>
>>> Fixes: 36077e16c050 ("phy: amlogic: Add Amlogic G12A USB3 + PCIE Combo PHY Driver")
>>> Signed-off-by: Neil Armstrong <[email protected]>
>>> ---
>>> drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c b/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
>>> index 6233a7979a93..ac322d643c7a 100644
>>> --- a/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
>>> +++ b/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
>>> @@ -188,7 +188,7 @@ static const struct regmap_config phy_g12a_usb3_pcie_cr_regmap_conf = {
>>> .reg_read = phy_g12a_usb3_pcie_cr_bus_read,
>>> .reg_write = phy_g12a_usb3_pcie_cr_bus_write,
>>> .max_register = 0xffff,
>>> - .fast_io = true,
>>> + .disable_locking = true,
>>> };
>>>
>>> static int phy_g12a_usb3_init(struct phy *phy)
>>>
>