When the board is booted without serial cable attached (which is how most of them will be used) UART RX is left floating and sometimes picks noise, which interrupts countdown and enters U-Boot prompt instead of booting the kernel.
Fix this by setting up internal pullup on UART RX pin. This does not prevent serial from working as the internal pullup is weak.
Signed-off-by: Grazvydas Ignotas notasas@gmail.com --- It would be nice for this to go in as a fix for 2009.11, else users without serial cable won't be able to boot it.
board/pandora/pandora.h | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/board/pandora/pandora.h b/board/pandora/pandora.h index 5bfa0f9..f0ad16b 100644 --- a/board/pandora/pandora.h +++ b/board/pandora/pandora.h @@ -219,7 +219,8 @@ const omap3_sysinfo sysinfo = { MUX_VAL(CP(UART2_RX), (IEN | PTD | EN | M4)) /*GPIO_147,*/\ /*UART2_RX*/\ /*Serial Interface (Peripheral boot, Linux console, on AV connector)*/\ - MUX_VAL(CP(UART3_RX_IRRX), (IEN | PTD | DIS | M0)) /*UART3_RX*/\ + /*RX pulled up to avoid noise when nothing is connected to serial port*/\ + MUX_VAL(CP(UART3_RX_IRRX), (IEN | PTU | EN | M0)) /*UART3_RX*/\ MUX_VAL(CP(UART3_TX_IRTX), (IDIS | PTD | DIS | M0)) /*UART3_TX*/\ /*LEDs (Controlled by OMAP)*/\ MUX_VAL(CP(MMC1_DAT6), (IDIS | PTD | DIS | M4)) /*GPIO_128*/\