Commit 0efa4f2c authored by Sonic Zhang's avatar Sonic Zhang Committed by Linus Torvalds
Browse files

Blackfin Serial Driver: annotate anomalies 05000215 and 05000099 



Add some comments for how these anomalies are addressed:

05000215 - UART TX Interrupt Masked Erroneously
We always clear ETBEI within last UART TX interrupt to end
a string.  It is always set when starting a new tx transfer.

05000099 - UART Line Status Register (UART_LSR) Bits Are Not Updated at
the Same Time
This anomaly affects driver only in POLL code where multi bits of
UART_LSR are checked. It doesn't affect current bfin_5xx.c driver.

Signed-off-by: default avatarSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 35ff6935

drivers/serial/bfin_5xx.c

+14 −0
Original line number Diff line number Diff line
@@ -330,6 +330,11 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart) 
		/* Clear TFI bit */

		UART_PUT_LSR(uart, TFI);

#endif

		/* Anomaly notes:

		 *  05000215 -	we always clear ETBEI within last UART TX

		 *		interrupt to end a string. It is always set

		 *		when start a new tx.

		 */

		UART_CLEAR_IER(uart, ETBEI);

		return;

	}
@@ -528,6 +533,11 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id) 
	if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {

		disable_dma(uart->tx_dma_channel);

		clear_dma_irqstat(uart->tx_dma_channel);

		/* Anomaly notes:

		 *  05000215 -	we always clear ETBEI within last UART TX

		 *		interrupt to end a string. It is always set

		 *		when start a new tx.

		 */

		UART_CLEAR_IER(uart, ETBEI);

		xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);

		uart->port.icount.tx += uart->tx_count;
@@ -969,6 +979,10 @@ static void bfin_serial_reset_irda(struct uart_port *port) 
}



#ifdef CONFIG_CONSOLE_POLL

/* Anomaly notes:

 *  05000099 -  Because we only use THRE in poll_put and DR in poll_get,

 *		losing other bits of UART_LSR is not a problem here.

 */

static void bfin_serial_poll_put_char(struct uart_port *port, unsigned char chr)

{

	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;

CRA Git | Maintained and supported by SUSTech CRA and CCSE