From: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
[ Upstream commit 4268254a39484fc11ba991ae148bacbe75d9cc0a ]
Instead of repeatedly calling clk_get_rate for each transfer, lock
the clock rate and cache the value.
A deadlock has been observed while adding tlv320aic32x4 audio codec to
the system. When this clock provider adds its clock, the clk mutex is
locked already, it needs to access i2c, which in return needs the mutex
for clk_get_rate as well.
Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
[ Don't call devm_clk_rate_exclusive_get() for devm_clk_rate_exclusive_get()
does not exist in v6.1. ]
Signed-off-by: Bin Lan <bin.lan.cn@xxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-imx-lpi2c.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index ff12018bc206..270197ac995a 100644
--- a/drivers/i2c/busses/i2c-imx-lpi2c.c
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -100,6 +100,7 @@ struct lpi2c_imx_struct {
__u8 *rx_buf;
__u8 *tx_buf;
struct completion complete;
+ unsigned long rate_per;
unsigned int msglen;
unsigned int delivered;
unsigned int block_data;
@@ -208,7 +209,8 @@ static int lpi2c_imx_config(struct lpi2c_imx_struct *lpi2c_imx)
lpi2c_imx_set_mode(lpi2c_imx);
- clk_rate = clk_get_rate(lpi2c_imx->clks[0].clk);
+ clk_rate = lpi2c_imx->rate_per;
+
if (lpi2c_imx->mode == HS || lpi2c_imx->mode == ULTRA_FAST)
filt = 0;
else
@@ -594,6 +596,11 @@ static int lpi2c_imx_probe(struct platform_device *pdev)
if (ret)
return ret;
+ lpi2c_imx->rate_per = clk_get_rate(lpi2c_imx->clks[0].clk);
+ if (!lpi2c_imx->rate_per)
+ return dev_err_probe(&pdev->dev, -EINVAL,
+ "can't get I2C peripheral clock rate\n");
+
pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_get_noresume(&pdev->dev);
--
2.43.0
