Difference between revisions of "CM-T43: Linux: Known Issues"
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| − | {{IssueCategory| | + | {{IssueCategory|RTC| |
| − | * | + | * RTC time and date is not maintained when unit is unplugged from power supply, even if an RTC backup battery is installed |
:'''Workaround:''' | :'''Workaround:''' | ||
| − | : | + | : Use the following U-Boot commands to enable battery supplied time keeping: <pre>pmic TPS65218_PMIC write 10 b1; pmic TPS65218_PMIC write 10 fe; pmic TPS65218_PMIC write 10 a3</pre> |
| + | : This sets the FSEAL bit, which forces the power supply for the RTC to stay on when the system is in the OFF state. | ||
| + | : Once set it will stay set until the battery is removed or the above commands are run again. | ||
| + | : More information on this bit can be found in section 8.5.2 of the TPS65218 manual. | ||
}} | }} | ||
| − | [[Category:Linux | + | {{IssueCategory|OPP| |
| − | [[Category:CM-T43 | + | * U-Boot versions 0.97 and below do not modify the PMIC voltages. The PMIC retains its settings between resets, and as a result if CM-T43 is switched to a low performance OPP (below 800 Mhz), on reset U-Boot will be using low performance voltage settings for a high performance CPU frequency and may not finish booting. |
| + | :'''Workaround:''' | ||
| + | : Switch to performance governor (default governor) before initiating resets. | ||
| + | }} | ||
| + | |||
| + | [[Category:Linux]] | ||
| + | [[Category:CM-T43]] | ||
Revision as of 09:43, 7 December 2015
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