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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Neil Armstrong <narmstrong@baylibre.com>,
        Kevin Hilman <khilman@baylibre.com>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        Sasha Levin <sashal@kernel.org>,
        linux-amlogic@lists.infradead.org
Subject: [PATCH AUTOSEL 5.2 088/171] phy: meson-g12a-usb3-pcie: disable locking for cr_regmap
Date:   Thu, 18 Jul 2019 23:55:19 -0400
Message-Id: <20190719035643.14300-88-sashal@kernel.org>
In-Reply-To: <20190719035643.14300-1-sashal@kernel.org>
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From: Neil Armstrong <narmstrong@baylibre.com>

[ Upstream commit 5fc2aa3ec9efad97dd7c316f3c8e4c6268bbed9b ]

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@baylibre.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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)
-- 
2.20.1