diff options
Diffstat (limited to 'plat/qti/msm8916/aarch64/uartdm_console.S')
-rw-r--r-- | plat/qti/msm8916/aarch64/uartdm_console.S | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/plat/qti/msm8916/aarch64/uartdm_console.S b/plat/qti/msm8916/aarch64/uartdm_console.S index e14217939..6c65daf04 100644 --- a/plat/qti/msm8916/aarch64/uartdm_console.S +++ b/plat/qti/msm8916/aarch64/uartdm_console.S @@ -1,5 +1,5 @@ /* - * Copyright (c) 2021-2022, Stephan Gerhold <stephan@gerhold.net> + * Copyright (c) 2021-2023, Stephan Gerhold <stephan@gerhold.net> * * Based on aarch64/skeleton_console.S: * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved. @@ -65,7 +65,21 @@ endfunc console_uartdm_register * ----------------------------------------------------------- */ func console_uartdm_core_init - /* Reset receiver */ + /* + * Try to flush remaining characters from the TX FIFO before resetting + * the transmitter. Unfortunately there is no good way to check if + * the transmitter is actually enabled (and will finish eventually), + * so use a timeout to avoid looping forever. + */ + mov w2, #65536 +1: + ldr w3, [x1, #UART_DM_SR] + tbnz w3, #UART_DM_SR_TXEMT_BIT, 2f + subs w2, w2, #1 + b.ne 1b + /* Timeout */ + +2: /* Reset receiver */ mov w3, #UART_DM_CR_RESET_RX str w3, [x1, #UART_DM_CR] |