i2c-imx: Driver fixes #21
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Like other i2c controllers we see deadlock issues with clock prepare mutex. I our case this came up with a clock output of a rtc connected to i2c bus. This issue has already been fixed upstream by: (d9a22d7) i2c: imx: avoid taking clk_prepare mutex in PM callbacks But was reintroduced by a wrongly resolved merge conflict with this commit: (66c0769) MLK-11403: I2C: imx: restore pin setting for i2c So again we keep the i2c clock prepared and only enable and disable it for a transfer. Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
As clk_get_rate() also keeps the clk prepare lock which can lead into a deadlock. It was removed upstream with this commit: (90ad2cb) i2c: imx: use clk notifier for rate changes But it has been readded again with: (0e94d44) MLK-20368 i2c-imx: Coverity: fix divide by zero warning The commit meassage does not explain why it was readded. It is not needed as the clk notifier is used. Removed it again. Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
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We are noticing boot lock ups in the past 3 or 4 NXP kernel releases on some of our i.MX8M boards. The hang is always related to our i2c RTC.
We figured out that the lock and mutex handing is done incorrect in the i2c-imx driver.
The issues where already resolved upstream but it seems that due not properly solved rebase conflicts in the past they have been reintroduced again.
Please see the commit messages of the patches for more detailed information. We would appreciate if the issues are being resolved in future so that we do not have to apply the patches for every release.