[PATCH v2] phy: meson-g12a-usb3-pcie: disable locking for cr_regmap

From: Neil Armstrong
Date: Wed Jun 05 2019 - 05:06:19 EST


Locking is not needed for the phy_g12a_usb3_pcie_cr_bus_read/write() and
currently it causes the following BUG because of the usage of the
regmap_read_poll_timeout() running in spinlock_irq, configured by regmap fast_io.

Simply disable locking in the cr_regmap config since it's only used from the
PHY init callback function.

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 <narmstrong@xxxxxxxxxxxx>
---
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