From: Erwan Le Ray erwan.leray@st.com
[ Upstream commit 4f01d833fdcdd6f9b85d9e5d5d7568eb683626a7 ]
- Fixes parity and framing error bit by clearing parity and framing error flag. The current implementation doesn't clear the error bits when an error is detected. - Fixes the incorrect name of framing error clearing flag in header file. - Fixes misalignement between data frame and errors status. The status read for "n" frame was the status of "n+1" frame". - Fixes break detection was not triggered by the expected register.
Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Signed-off-by: Erwan Le Ray erwan.leray@st.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/stm32-usart.c | 54 +++++++++++++++++++++----------- drivers/tty/serial/stm32-usart.h | 10 ++---- 2 files changed, 37 insertions(+), 27 deletions(-)
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index e8321850938af..f6b739351ddec 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -225,35 +225,51 @@ static void stm32_receive_chars(struct uart_port *port, bool threaded)
while (stm32_pending_rx(port, &sr, &stm32_port->last_res, threaded)) { sr |= USART_SR_DUMMY_RX; - c = stm32_get_char(port, &sr, &stm32_port->last_res); flag = TTY_NORMAL; - port->icount.rx++;
+ /* + * Status bits has to be cleared before reading the RDR: + * In FIFO mode, reading the RDR will pop the next data + * (if any) along with its status bits into the SR. + * Not doing so leads to misalignement between RDR and SR, + * and clear status bits of the next rx data. + * + * Clear errors flags for stm32f7 and stm32h7 compatible + * devices. On stm32f4 compatible devices, the error bit is + * cleared by the sequence [read SR - read DR]. + */ + if ((sr & USART_SR_ERR_MASK) && ofs->icr != UNDEF_REG) + stm32_clr_bits(port, ofs->icr, USART_ICR_ORECF | + USART_ICR_PECF | USART_ICR_FECF); + + c = stm32_get_char(port, &sr, &stm32_port->last_res); + port->icount.rx++; if (sr & USART_SR_ERR_MASK) { - if (sr & USART_SR_LBD) { - port->icount.brk++; - if (uart_handle_break(port)) - continue; - } else if (sr & USART_SR_ORE) { - if (ofs->icr != UNDEF_REG) - writel_relaxed(USART_ICR_ORECF, - port->membase + - ofs->icr); + if (sr & USART_SR_ORE) { port->icount.overrun++; } else if (sr & USART_SR_PE) { port->icount.parity++; } else if (sr & USART_SR_FE) { - port->icount.frame++; + /* Break detection if character is null */ + if (!c) { + port->icount.brk++; + if (uart_handle_break(port)) + continue; + } else { + port->icount.frame++; + } }
sr &= port->read_status_mask;
- if (sr & USART_SR_LBD) - flag = TTY_BREAK; - else if (sr & USART_SR_PE) + if (sr & USART_SR_PE) { flag = TTY_PARITY; - else if (sr & USART_SR_FE) - flag = TTY_FRAME; + } else if (sr & USART_SR_FE) { + if (!c) + flag = TTY_BREAK; + else + flag = TTY_FRAME; + } }
if (uart_handle_sysrq_char(port, c)) @@ -721,14 +737,14 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios, if (termios->c_iflag & INPCK) port->read_status_mask |= USART_SR_PE | USART_SR_FE; if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) - port->read_status_mask |= USART_SR_LBD; + port->read_status_mask |= USART_SR_FE;
/* Characters to ignore */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) port->ignore_status_mask = USART_SR_PE | USART_SR_FE; if (termios->c_iflag & IGNBRK) { - port->ignore_status_mask |= USART_SR_LBD; + port->ignore_status_mask |= USART_SR_FE; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h index a70aa5006ab97..8d34802e572ed 100644 --- a/drivers/tty/serial/stm32-usart.h +++ b/drivers/tty/serial/stm32-usart.h @@ -108,7 +108,6 @@ struct stm32_usart_info stm32h7_info = { #define USART_SR_RXNE BIT(5) #define USART_SR_TC BIT(6) #define USART_SR_TXE BIT(7) -#define USART_SR_LBD BIT(8) #define USART_SR_CTSIF BIT(9) #define USART_SR_CTS BIT(10) /* F7 */ #define USART_SR_RTOF BIT(11) /* F7 */ @@ -120,8 +119,7 @@ struct stm32_usart_info stm32h7_info = { #define USART_SR_SBKF BIT(18) /* F7 */ #define USART_SR_WUF BIT(20) /* H7 */ #define USART_SR_TEACK BIT(21) /* F7 */ -#define USART_SR_ERR_MASK (USART_SR_LBD | USART_SR_ORE | \ - USART_SR_FE | USART_SR_PE) +#define USART_SR_ERR_MASK (USART_SR_ORE | USART_SR_FE | USART_SR_PE) /* Dummy bits */ #define USART_SR_DUMMY_RX BIT(16)
@@ -168,8 +166,6 @@ struct stm32_usart_info stm32h7_info = { /* USART_CR2 */ #define USART_CR2_ADD_MASK GENMASK(3, 0) /* F4 */ #define USART_CR2_ADDM7 BIT(4) /* F7 */ -#define USART_CR2_LBDL BIT(5) -#define USART_CR2_LBDIE BIT(6) #define USART_CR2_LBCL BIT(8) #define USART_CR2_CPHA BIT(9) #define USART_CR2_CPOL BIT(10) @@ -226,12 +222,10 @@ struct stm32_usart_info stm32h7_info = {
/* USART_ICR */ #define USART_ICR_PECF BIT(0) /* F7 */ -#define USART_ICR_FFECF BIT(1) /* F7 */ -#define USART_ICR_NCF BIT(2) /* F7 */ +#define USART_ICR_FECF BIT(1) /* F7 */ #define USART_ICR_ORECF BIT(3) /* F7 */ #define USART_ICR_IDLECF BIT(4) /* F7 */ #define USART_ICR_TCCF BIT(6) /* F7 */ -#define USART_ICR_LBDCF BIT(8) /* F7 */ #define USART_ICR_CTSCF BIT(9) /* F7 */ #define USART_ICR_RTOCF BIT(11) /* F7 */ #define USART_ICR_EOBCF BIT(12) /* F7 */