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| author | Nicolas Boichat <drinkcat@chromium.org> | 2018-12-12 16:53:35 +0800 |
|---|---|---|
| committer | chrome-bot <chrome-bot@chromium.org> | 2018-12-23 14:46:08 -0800 |
| commit | 4c98d54c19702fdad5864ae6518913a21b64b192 (patch) | |
| tree | 31be5fd62431ccebc1c144f4a09cc6809f48a2e2 | |
| parent | 9b9ca849029d804a3cc99bbe2854b22ae2cb0207 (diff) | |
| download | chrome-ec-4c98d54c19702fdad5864ae6518913a21b64b192.tar.gz | |
mt_scp/uart: Do not use usleep in tx_flush/write_char
These functions may be called in interrupt/exception context,
especially when panic_printf is used. We need to busy-loop.
BRANCH=none
BUG=b:119929419
TEST=crash divzero works
Change-Id: Ie97243afcc433226e78ea1b1225227c6ffbf2a04
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1373288
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Reviewed-by: Yilun Lin <yllin@chromium.org>
| -rw-r--r-- | chip/mt_scp/uart.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/chip/mt_scp/uart.c b/chip/mt_scp/uart.c index 73a284319c..94f78748dd 100644 --- a/chip/mt_scp/uart.c +++ b/chip/mt_scp/uart.c @@ -15,7 +15,6 @@ /* Console UART index */ #define UARTN CONFIG_UART_CONSOLE -#define UART_WAIT_US 50 #define UART_IDLE_WAIT_US 500 static uint8_t uart_done, tx_started; @@ -58,7 +57,7 @@ void uart_tx_stop(void) void uart_tx_flush(void) { while (!(UART_LSR(UARTN) & UART_LSR_TEMT)) - usleep(UART_WAIT_US); + ; } int uart_tx_ready(void) @@ -76,7 +75,7 @@ int uart_rx_available(void) void uart_write_char(char c) { while (!uart_tx_ready()) - usleep(UART_WAIT_US); + ; UART_DATA(UARTN) = c; } |