From 7b3b74d321279b8aaee448d136fa9d20f8fd0739 Mon Sep 17 00:00:00 2001 From: Patrice Chotard Date: Fri, 20 Apr 2018 08:59:06 +0200 Subject: serial: serial_stm32: Enable overrun Enable uart overrun feature which allows to benefits of uart FIFO usage. Previously overrun management was disabled, this has to effect to bypassed the uart FIFO usage even if FIFO was enabled. In particular configuration, for example when video console is enabled, copy/pasting a long command line in console results in corruption. This is due to the fact that a lot of time is consumed in flushing the cache during frame buffer update, so uart chars are not read fast enough. By using uart FIFO and managing overrun, long command line can by copy/paste in console without being corrupted. Signed-off-by: Patrice Chotard --- drivers/serial/serial_stm32.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'drivers/serial/serial_stm32.c') diff --git a/drivers/serial/serial_stm32.c b/drivers/serial/serial_stm32.c index dfef0d47e5f..e2eeadef9da 100644 --- a/drivers/serial/serial_stm32.c +++ b/drivers/serial/serial_stm32.c @@ -43,10 +43,19 @@ static int stm32_serial_getc(struct udevice *dev) struct stm32x7_serial_platdata *plat = dev_get_platdata(dev); bool stm32f4 = plat->uart_info->stm32f4; fdt_addr_t base = plat->base; + u32 isr = readl(base + ISR_OFFSET(stm32f4)); - if ((readl(base + ISR_OFFSET(stm32f4)) & USART_SR_FLAG_RXNE) == 0) + if ((isr & USART_SR_FLAG_RXNE) == 0) return -EAGAIN; + if (isr & USART_SR_FLAG_ORE) { + if (!stm32f4) + setbits_le32(base + ICR_OFFSET, USART_ICR_OREF); + else + readl(base + RDR_OFFSET(stm32f4)); + return -EIO; + } + return readl(base + RDR_OFFSET(stm32f4)); } @@ -107,11 +116,9 @@ static int stm32_serial_probe(struct udevice *dev) return plat->clock_rate; }; - /* Disable uart-> disable overrun-> enable uart */ + /* Disable uart-> enable fifo-> enable uart */ clrbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_RE | USART_CR1_TE | BIT(uart_enable_bit)); - if (plat->uart_info->has_overrun_disable) - setbits_le32(base + CR3_OFFSET(stm32f4), USART_CR3_OVRDIS); if (plat->uart_info->has_fifo) setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_FIFOEN); setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_RE | USART_CR1_TE | -- cgit v1.2.3