Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760484AbZFBHNw (ORCPT ); Tue, 2 Jun 2009 03:13:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759478AbZFBHLy (ORCPT ); Tue, 2 Jun 2009 03:11:54 -0400 Received: from smtp.gentoo.org ([140.211.166.183]:46640 "EHLO smtp.gentoo.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758919AbZFBHLv (ORCPT ); Tue, 2 Jun 2009 03:11:51 -0400 From: Mike Frysinger To: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Cc: uclinux-dist-devel@blackfin.uclinux.org, Sonic Zhang Subject: [PATCH 09/11] Blackfin Serial Driver: annotate anomalies 05000215 and 05000099 Date: Tue, 2 Jun 2009 03:11:38 -0400 Message-Id: <1243926700-30485-9-git-send-email-vapier@gentoo.org> X-Mailer: git-send-email 1.6.3.1 In-Reply-To: <1243926700-30485-1-git-send-email-vapier@gentoo.org> References: <1243926700-30485-1-git-send-email-vapier@gentoo.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2439 Lines: 66 From: Sonic Zhang 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 Signed-off-by: Mike Frysinger --- drivers/serial/bfin_5xx.c | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c index 854e96d..ab583ef 100644 --- a/drivers/serial/bfin_5xx.c +++ b/drivers/serial/bfin_5xx.c @@ -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; -- 1.6.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/