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authorJensen Huang <jensenhuang@friendlyarm.com>2023-12-07 11:21:59 +0300
committerWolfram Sang <wsa@kernel.org>2023-12-19 20:23:01 +0300
commit19cde9c92b8d3b7ee555d0da3bcb0232d3a784f4 (patch)
treef96a1a9e1427b5d1cb35d1f4a6ef09a63216a9fa
parent043465b66506e8c647cdd38a2db1f2ee0f369a1b (diff)
downloadlinux-19cde9c92b8d3b7ee555d0da3bcb0232d3a784f4.tar.xz
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>
-rw-r--r--drivers/i2c/busses/i2c-rk3x.c13
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) {