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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: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@ -330,6 +330,11 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
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/* Clear TFI bit */
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UART_PUT_LSR(uart, TFI);
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#endif
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/* Anomaly notes:
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* 05000215 - we always clear ETBEI within last UART TX
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* interrupt to end a string. It is always set
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* when start a new tx.
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*/
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UART_CLEAR_IER(uart, ETBEI);
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return;
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}
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@ -528,6 +533,11 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
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if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
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disable_dma(uart->tx_dma_channel);
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clear_dma_irqstat(uart->tx_dma_channel);
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/* Anomaly notes:
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* 05000215 - we always clear ETBEI within last UART TX
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* interrupt to end a string. It is always set
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* when start a new tx.
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*/
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UART_CLEAR_IER(uart, ETBEI);
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xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
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uart->port.icount.tx += uart->tx_count;
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@ -969,6 +979,10 @@ static void bfin_serial_reset_irda(struct uart_port *port)
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}
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#ifdef CONFIG_CONSOLE_POLL
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/* Anomaly notes:
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* 05000099 - Because we only use THRE in poll_put and DR in poll_get,
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* losing other bits of UART_LSR is not a problem here.
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*/
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static void bfin_serial_poll_put_char(struct uart_port *port, unsigned char chr)
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{
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struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
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