.. include:: ../defs.txt

.. _librem_5_known_issues_birch:

Birch
=====

This page contains the known issues for the Birch shipment of phones as supplied to users.

 * When charging the phone using a charger, 12V negotiation and rapid charging can fail.
   |gap|
   To help prevent this, follow these step to charge the phone:

      * Unplug the power adapter (wall wart) from the power outlet.
      * Plug one end of the USB-cable into the adapter and the other end into the phone.
      * Plug the adapter into the power outlet.

   When unplugging:

      * Unplug the adapter from the power outlet first.
      * Then unplug the USB-C cable from the phone.

   If this failure occurs, USB 2.0 data transmission can also be affected. This failure mode does not affect 5V charging over a USB type-C to USB type-A cable.

 * After being powered down, the phone can be difficult to power up again.

   This problem is related to a software issue which was fixed after the phones were shipped: `Power Button Not Turning Device Back On <linux-next-109_>`_

   The solution for a phone with the original software is to unplug the USB cable, then press the power button for 15-18 seconds.
   |gap|

 * Call audio routing is not functioning completely.

   This issue will be fixed in an upcoming system update.
   |gap|

 * The battery installed in the phone is labelled with a capacity of 2000 mAh.

   This is a conservative estimate of the capacity. Later iterations of the phone should have higher capacity batteries.
   |gap|

 * Power management and heat issues are caused by various subsystems. The processor will be run more slowly to prevent overheating, affecting processing performance.
   |gap|

 * The phone may sometimes restart when turning the modem on using the kill switch.

   This depends on the modem in use. BroadMobi BM818-A1/E1 modems do not seem to be affected.
   |gap|

 * The phone may restart if you remove or insert the SIM card while it is powered.

   This is due to the type of SIM tray in use. **Users should power off the phone before replacing SIM cards.**
   |gap|

 * Any installed microSD card can only be read from and not written to. This is a limitation of the Birch hardware.
   |gap|

 * Activation of rapid charging depends on whether the TPS65982 power controller is first powered via USB or via the battery.
   |gap|

 * Rapid charging is currently not possible over a USB A to C cable due to a software issue: `BQ25895: Disable BC1.2 and Set IINLIM to Max Value <linux-next-135_>`_
   |gap|

 * The GNSS module is unable to reliably receive broadcasts from satellites, making it difficult to fix the location of the phone. This problem will be addressed in later revisions of the hardware, from Dogwood onwards.
