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i2c: rk3x: fix potential spinlock recursion on poll

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[ Upstream commit 19cde9c92b ]

Possible deadlock scenario (on reboot):
rk3x_i2c_xfer_common(polling)
    -> rk3x_i2c_wait_xfer_poll()
        -> rk3x_i2c_irq(0, i2c);
            --> spin_lock(&i2c->lock);
            ...
        <rk3x i2c interrupt>
        -> rk3x_i2c_irq(0, i2c);
            --> spin_lock(&i2c->lock); (deadlock here)

Store the IRQ number and disable/enable it around the polling transfer.
This patch has been tested on NanoPC-T4.

Signed-off-by: Jensen Huang <jensenhuang@friendlyarm.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jensen Huang 2023-12-07 16:21:59 +08:00 committed by Greg Kroah-Hartman
parent 3f0dc646b5
commit c9f5b801bc
1 changed files with 11 additions and 2 deletions
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13
drivers/i2c/busses/i2c-rk3x.c
View file

@ -178,6 +178,7 @@ struct rk3x_i2c_soc_data {
* @clk: function clk for rk3399 or function & Bus clks for others
* @pclk: Bus clk for rk3399
* @clk_rate_nb: i2c clk rate change notify
* @irq: irq number
* @t: I2C known timing information
* @lock: spinlock for the i2c bus
* @wait: the waitqueue to wait for i2c transfer
@ -200,6 +201,7 @@ struct rk3x_i2c {
struct clk *clk;
struct clk *pclk;
struct notifier_block clk_rate_nb;
int irq;
/* Settings */
struct i2c_timings t;
@ -1087,13 +1089,18 @@ static int rk3x_i2c_xfer_common(struct i2c_adapter *adap,
spin_unlock_irqrestore(&i2c->lock, flags);
rk3x_i2c_start(i2c);
if (!polling) {
rk3x_i2c_start(i2c);
timeout = wait_event_timeout(i2c->wait, !i2c->busy,
msecs_to_jiffies(WAIT_TIMEOUT));
} else {
disable_irq(i2c->irq);
rk3x_i2c_start(i2c);
timeout = rk3x_i2c_wait_xfer_poll(i2c);
enable_irq(i2c->irq);
}
spin_lock_irqsave(&i2c->lock, flags);
@ -1301,6 +1308,8 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
return ret;
}
i2c->irq = irq;
platform_set_drvdata(pdev, i2c);
if (i2c->soc_data->calc_timings == rk3x_i2c_v0_calc_timings) {