diff options
Diffstat (limited to 'target/linux/layerscape/patches-5.4/808-i2c-0010-i2c-imx-fix-system-hang-due-to-access-i2c-registers-.patch')
| -rw-r--r-- | target/linux/layerscape/patches-5.4/808-i2c-0010-i2c-imx-fix-system-hang-due-to-access-i2c-registers-.patch | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/target/linux/layerscape/patches-5.4/808-i2c-0010-i2c-imx-fix-system-hang-due-to-access-i2c-registers-.patch b/target/linux/layerscape/patches-5.4/808-i2c-0010-i2c-imx-fix-system-hang-due-to-access-i2c-registers-.patch new file mode 100644 index 0000000000..0d80b9edd8 --- /dev/null +++ b/target/linux/layerscape/patches-5.4/808-i2c-0010-i2c-imx-fix-system-hang-due-to-access-i2c-registers-.patch @@ -0,0 +1,52 @@ +From 97db2ca4485dc7b10b8382832befe607ade59a6b Mon Sep 17 00:00:00 2001 +From: Dong Aisheng <aisheng.dong@nxp.com> +Date: Sat, 26 Jan 2019 17:51:59 +0800 +Subject: [PATCH] i2c: imx: fix system hang due to access i2c registers without + clock + +Currently, i2c_imx_bus_busy in i2c_imx_xfer is called before +pm_runtime_get which means the clocks are still not enabled. +This will cause a hang on IMX as IMX requires accessing registers +with clocks. + +So let's change the order to ensure the clocks are enabled before +accessing registers. This is also a more safe way to access registers, +suppose shouldn't affect other platforms. + +Fixes: 4a6ebf1c125c ("i2c: imx: add workaround for erratum ERR010027") +Reviewed-by: Biwen Li <biwen.li@nxp.com> +Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> +--- + drivers/i2c/busses/i2c-imx.c | 9 ++++----- + 1 file changed, 4 insertions(+), 5 deletions(-) + +--- a/drivers/i2c/busses/i2c-imx.c ++++ b/drivers/i2c/busses/i2c-imx.c +@@ -1066,12 +1066,15 @@ static int i2c_imx_xfer(struct i2c_adapt + + dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__); + +- + if (!pm_runtime_enabled(i2c_imx->adapter.dev.parent)) { + pm_runtime_enable(i2c_imx->adapter.dev.parent); + enable_runtime_pm = true; + } + ++ result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent); ++ if (result < 0) ++ goto out; ++ + /* + * workround for ERR010027: ensure that the I2C BUS is idle + * before switching to master mode and attempting a Start cycle +@@ -1085,10 +1088,6 @@ static int i2c_imx_xfer(struct i2c_adapt + goto out; + } + +- result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent); +- if (result < 0) +- goto out; +- + /* Start I2C transfer */ + result = i2c_imx_start(i2c_imx); + if (result) { |