On 10/10/2017 11:22 PM, Han, Nandor (GE Healthcare) wrote: > > >> -----Original Message----- >> From: linux-serial-owner@xxxxxxxxxxxxxxx [mailto:linux-serial- >> owner@xxxxxxxxxxxxxxx] On Behalf Of Troy Kisky >> Sent: 07 October 2017 04:47 >> To: gregkh@xxxxxxxxxxxxxxxxxxx >> Cc: fabio.estevam@xxxxxxx; l.stach@xxxxxxxxxxxxxx; u.kleine- >> koenig@xxxxxxxxxxxxxx; linux-serial@xxxxxxxxxxxxxxx; linux-arm- >> kernel@xxxxxxxxxxxxxxxxxxx; Troy Kisky <troy.kisky@xxxxxxxxxxxxxxxxxxx> >> Subject: EXT: [PATCH 1/1] tty: serial: imx: disable ageing timer interrupt if >> dma in use >> >> Since commit 4dec2f119e86 ("imx-serial: RX DMA startup latency") >> >> the interrupt routine no longer will start rx dma. > > I think you have 2 commits here: > - one that disables ageing timer when DMA is in use > - one that cleans the leftovers after 4dec2f119e86. > I could kill 3 lines, in the 1st patch, and the other 27 in the next. But the 2 patches would not be independent. You should not apply the second without the 1st. I think the change is simple enough not to warrant a series. >> >> Signed-off-by: Troy Kisky <troy.kisky@xxxxxxxxxxxxxxxxxxx> >> --- >> drivers/tty/serial/imx.c | 34 ++-------------------------------- >> 1 file changed, 2 insertions(+), 32 deletions(-) >> >> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index >> dfeff3951f93..15b0ecb4cf60 100644 >> --- a/drivers/tty/serial/imx.c >> +++ b/drivers/tty/serial/imx.c >> @@ -732,29 +732,6 @@ static void imx_disable_rx_int(struct imx_port >> *sport) } >> >> static void clear_rx_errors(struct imx_port *sport); -static int >> start_rx_dma(struct imx_port *sport); >> -/* >> - * If the RXFIFO is filled with some data, and then we >> - * arise a DMA operation to receive them. >> - */ >> -static void imx_dma_rxint(struct imx_port *sport) -{ >> - unsigned long temp; >> - unsigned long flags; >> - >> - spin_lock_irqsave(&sport->port.lock, flags); >> - >> - temp = readl(sport->port.membase + USR2); >> - if ((temp & USR2_RDR) && !sport->dma_is_rxing) { >> - >> - imx_disable_rx_int(sport); >> - >> - /* tell the DMA to receive the data. */ >> - start_rx_dma(sport); >> - } >> - >> - spin_unlock_irqrestore(&sport->port.lock, flags); >> -} >> >> /* >> * We have a modem side uart, so the meanings of RTS and CTS are inverted. >> @@ -816,11 +793,8 @@ static irqreturn_t imx_int(int irq, void *dev_id) >> sts = readl(sport->port.membase + USR1); >> sts2 = readl(sport->port.membase + USR2); >> >> - if (sts & (USR1_RRDY | USR1_AGTIM)) { >> - if (sport->dma_is_enabled) >> - imx_dma_rxint(sport); >> - else >> - imx_rxint(irq, dev_id); >> + if (!sport->dma_is_enabled && (sts & (USR1_RRDY | >> USR1_AGTIM))) { >> + imx_rxint(irq, dev_id); > > I don't think we need the check `!sport->dma_is_enabled ` since RRDY and AGTIM interrupts should be disable when DMA is enabled. If I AND the status with its corresponding interrupt enable. But that is just as complicated, and more different from the original. > >> ret = IRQ_HANDLED; >> } >> >> @@ -1207,10 +1181,6 @@ static void imx_enable_dma(struct imx_port >> *sport) >> temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN; >> writel(temp, sport->port.membase + UCR1); >> >> - temp = readl(sport->port.membase + UCR2); >> - temp |= UCR2_ATEN; >> - writel(temp, sport->port.membase + UCR2); >> - > > I think this should be moved to imx_startup. At least RRDY is configured there. > Currently, non-dma mode does not use the ageing timer. You get an interrupt immediately when 1 character is in the fifo. So, enabling the ageing timer and changing fifo level, should really be a separate patch. But it would be a nice patch. -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
