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| author | Jensen Huang <jensenhuang@friendlyarm.com> | 2023-12-07 16:21:59 +0800 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2023-12-19 18:23:01 +0100 |
| commit | 19cde9c92b8d3b7ee555d0da3bcb0232d3a784f4 (patch) | |
| tree | f96a1a9e1427b5d1cb35d1f4a6ef09a63216a9fa /drivers/i2c | |
| parent | 043465b66506e8c647cdd38a2db1f2ee0f369a1b (diff) | |
| download | linux-19cde9c92b8d3b7ee555d0da3bcb0232d3a784f4.tar.gz linux-19cde9c92b8d3b7ee555d0da3bcb0232d3a784f4.tar.bz2 linux-19cde9c92b8d3b7ee555d0da3bcb0232d3a784f4.zip | |
i2c: rk3x: fix potential spinlock recursion on poll
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>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-rk3x.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c index a044ca0c35a1..4362db7c5789 100644 --- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -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); @@ -1310,6 +1317,8 @@ 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) { |