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Commit 0bcfd70e authored by Mike Frysinger's avatar Mike Frysinger Committed by Bryan Wu
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[Blackfin] serial driver: fix bug - cache the bits of the LSR on systems where... 


[Blackfin] serial driver: fix bug - cache the bits of the LSR on systems where the LSR is read-to-clear

Cache the bits of the LSR on systems where the LSR is read-to-clear
so that we can safely read the LSR in random places.  this fixes
older parts where break/framing/parity/overflow was not being detected
at all in PIO mode, and this fixes newer parts where
break/framing/parity/overflow was being reported all the time
without being cleared.

Signed-off-by: default avatarMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: default avatarBryan Wu <bryan.wu@analog.com>
parent 4c195ad8

drivers/serial/bfin_5xx.c

+7 −3
Original line number Diff line number Diff line
@@ -216,8 +216,10 @@ static void bfin_serial_rx_chars(struct bfin_serial_port *uart) 
	struct pt_regs *regs = get_irq_regs();

#endif



 	ch = UART_GET_CHAR(uart);

	status = UART_GET_LSR(uart);

	UART_CLEAR_LSR(uart);



 	ch = UART_GET_CHAR(uart);

 	uart->port.icount.rx++;



#ifdef CONFIG_KGDB_UART
@@ -335,7 +337,7 @@ static irqreturn_t bfin_serial_rx_int(int irq, void *dev_id) 
	struct bfin_serial_port *uart = dev_id;



	spin_lock(&uart->port.lock);

	while ((UART_GET_IER(uart) & ERBFI) && (UART_GET_LSR(uart) & DR))

	while (UART_GET_LSR(uart) & DR)

		bfin_serial_rx_chars(uart);

	spin_unlock(&uart->port.lock);
@@ -347,7 +349,7 @@ static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id) 
	struct bfin_serial_port *uart = dev_id;



	spin_lock(&uart->port.lock);

	if ((UART_GET_IER(uart) & ETBEI) && (UART_GET_LSR(uart) & THRE))

	if (UART_GET_LSR(uart) & THRE)

		bfin_serial_tx_chars(uart);

	spin_unlock(&uart->port.lock);
@@ -428,6 +430,8 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart) 
	int i, flg, status;



	status = UART_GET_LSR(uart);

	UART_CLEAR_LSR(uart);



	uart->port.icount.rx += CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail, UART_XMIT_SIZE);;



	if (status & BI) {

include/asm-blackfin/mach-bf527/bfin_serial_5xx.h

+18 −1
Original line number Diff line number Diff line
@@ -23,7 +23,6 @@ 
#define UART_GET_DLH(uart)	bfin_read16(((uart)->port.membase + OFFSET_DLH))

#define UART_GET_IIR(uart)      bfin_read16(((uart)->port.membase + OFFSET_IIR))

#define UART_GET_LCR(uart)      bfin_read16(((uart)->port.membase + OFFSET_LCR))

#define UART_GET_LSR(uart)      bfin_read16(((uart)->port.membase + OFFSET_LSR))

#define UART_GET_GCTL(uart)     bfin_read16(((uart)->port.membase + OFFSET_GCTL))



#define UART_PUT_CHAR(uart, v)   bfin_write16(((uart)->port.membase + OFFSET_THR), v)
@@ -58,6 +57,7 @@ 
struct bfin_serial_port {

	struct uart_port port;

	unsigned int old_status;

	unsigned int lsr;

#ifdef CONFIG_SERIAL_BFIN_DMA

	int tx_done;

	int tx_count;
@@ -76,6 +76,23 @@ struct bfin_serial_port { 
#endif

};



/* The hardware clears the LSR bits upon read, so we need to cache

 * some of the more fun bits in software so they don't get lost

 * when checking the LSR in other code paths (TX).

 */

static inline unsigned int UART_GET_LSR(struct bfin_serial_port *uart)

{

	unsigned int lsr = bfin_read16(uart->port.membase + OFFSET_LSR);

	uart->lsr |= (lsr & (BI|FE|PE|OE));

	return lsr | uart->lsr;

}



static inline void UART_CLEAR_LSR(struct bfin_serial_port *uart)

{

	uart->lsr = 0;

	bfin_write16(uart->port.membase + OFFSET_LSR, -1);

}



struct bfin_serial_port bfin_serial_ports[NR_PORTS];

struct bfin_serial_res {

	unsigned long uart_base_addr;

include/asm-blackfin/mach-bf533/bfin_serial_5xx.h

+18 −1
Original line number Diff line number Diff line
@@ -23,7 +23,6 @@ 
#define UART_GET_DLH(uart)	bfin_read16(((uart)->port.membase + OFFSET_DLH))

#define UART_GET_IIR(uart)      bfin_read16(((uart)->port.membase + OFFSET_IIR))

#define UART_GET_LCR(uart)      bfin_read16(((uart)->port.membase + OFFSET_LCR))

#define UART_GET_LSR(uart)      bfin_read16(((uart)->port.membase + OFFSET_LSR))

#define UART_GET_GCTL(uart)     bfin_read16(((uart)->port.membase + OFFSET_GCTL))



#define UART_PUT_CHAR(uart,v)   bfin_write16(((uart)->port.membase + OFFSET_THR),v)
@@ -46,6 +45,7 @@ 
struct bfin_serial_port {

        struct uart_port        port;

        unsigned int            old_status;

	unsigned int lsr;

#ifdef CONFIG_SERIAL_BFIN_DMA

	int			tx_done;

	int			tx_count;
@@ -64,6 +64,23 @@ struct bfin_serial_port { 
#endif

};



/* The hardware clears the LSR bits upon read, so we need to cache

 * some of the more fun bits in software so they don't get lost

 * when checking the LSR in other code paths (TX).

 */

static inline unsigned int UART_GET_LSR(struct bfin_serial_port *uart)

{

	unsigned int lsr = bfin_read16(uart->port.membase + OFFSET_LSR);

	uart->lsr |= (lsr & (BI|FE|PE|OE));

	return lsr | uart->lsr;

}



static inline void UART_CLEAR_LSR(struct bfin_serial_port *uart)

{

	uart->lsr = 0;

	bfin_write16(uart->port.membase + OFFSET_LSR, -1);

}



struct bfin_serial_port bfin_serial_ports[NR_PORTS];

struct bfin_serial_res {

	unsigned long	uart_base_addr;

include/asm-blackfin/mach-bf537/bfin_serial_5xx.h

+18 −1
Original line number Diff line number Diff line
@@ -23,7 +23,6 @@ 
#define UART_GET_DLH(uart)	bfin_read16(((uart)->port.membase + OFFSET_DLH))

#define UART_GET_IIR(uart)      bfin_read16(((uart)->port.membase + OFFSET_IIR))

#define UART_GET_LCR(uart)      bfin_read16(((uart)->port.membase + OFFSET_LCR))

#define UART_GET_LSR(uart)      bfin_read16(((uart)->port.membase + OFFSET_LSR))

#define UART_GET_GCTL(uart)     bfin_read16(((uart)->port.membase + OFFSET_GCTL))



#define UART_PUT_CHAR(uart,v)   bfin_write16(((uart)->port.membase + OFFSET_THR),v)
@@ -58,6 +57,7 @@ 
struct bfin_serial_port {

        struct uart_port        port;

        unsigned int            old_status;

	unsigned int lsr;

#ifdef CONFIG_SERIAL_BFIN_DMA

	int			tx_done;

	int			tx_count;
@@ -76,6 +76,23 @@ struct bfin_serial_port { 
#endif

};



/* The hardware clears the LSR bits upon read, so we need to cache

 * some of the more fun bits in software so they don't get lost

 * when checking the LSR in other code paths (TX).

 */

static inline unsigned int UART_GET_LSR(struct bfin_serial_port *uart)

{

	unsigned int lsr = bfin_read16(uart->port.membase + OFFSET_LSR);

	uart->lsr |= (lsr & (BI|FE|PE|OE));

	return lsr | uart->lsr;

}



static inline void UART_CLEAR_LSR(struct bfin_serial_port *uart)

{

	uart->lsr = 0;

	bfin_write16(uart->port.membase + OFFSET_LSR, -1);

}



struct bfin_serial_port bfin_serial_ports[NR_PORTS];

struct bfin_serial_res {

	unsigned long	uart_base_addr;

include/asm-blackfin/mach-bf548/bfin_serial_5xx.h

+1 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 
#define UART_PUT_DLH(uart,v)    bfin_write16(((uart)->port.membase + OFFSET_DLH),v)

#define UART_PUT_LSR(uart,v)	bfin_write16(((uart)->port.membase + OFFSET_LSR),v)

#define UART_PUT_LCR(uart,v)    bfin_write16(((uart)->port.membase + OFFSET_LCR),v)

#define UART_CLEAR_LSR(uart)    bfin_write16(((uart)->port.membase + OFFSET_LSR), -1)

#define UART_PUT_GCTL(uart,v)   bfin_write16(((uart)->port.membase + OFFSET_GCTL),v)



#if defined(CONFIG_BFIN_UART0_CTSRTS) || defined(CONFIG_BFIN_UART1_CTSRTS)