From: frans.klaver@xsens.com (Frans Klaver) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 13/16] tty: serial: 8250_dma: add pm runtime Date: Mon, 29 Sep 2014 11:26:06 +0200 Message-ID: <20140929092606.GC13952@ci00147.xsens-tech.local> (raw) In-Reply-To: <1410377411-26656-14-git-send-email-bigeasy@linutronix.de> On Wed, Sep 10, 2014 at 09:30:08PM +0200, Sebastian Andrzej Siewior wrote: > There is nothing to do for RPM in the RX path. If the HW goes off then it > won't assert the DMA line and the transfer won't happen. So we hope that > the HW does not go off for RX to work (DMA or PIO makes no difference > here). > > For TX the situation is slightly different. RPM is enabled on > start_tx(). We can't disable RPM on DMA complete callback because there > is still data in the FIFO which is being sent. We have to wait until > the FIFO is empty before we disable it. > For this to happen we fake a TX sent error and enable THRI. Once the > FIFO is empty we receive an interrupt and since the TTY-buffer is still > empty we "put RPM" via __stop_tx(). Should it been filed then in the > start_tx() path we should program the DMA transfer and remove the error > flag and the THRI bit. That last sentence starts out a bit messy. > > Reviewed-by: Tony Lindgren <tony@atomide.com> > Tested-by: Tony Lindgren <tony@atomide.com> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > --- > drivers/tty/serial/8250/8250_dma.c | 16 +++++++++++----- > 1 file changed, 11 insertions(+), 5 deletions(-) > > diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c > index 898a6781d0b3..e8850219b150 100644 > --- a/drivers/tty/serial/8250/8250_dma.c > +++ b/drivers/tty/serial/8250/8250_dma.c > @@ -21,6 +21,7 @@ static void __dma_tx_complete(void *param) > struct uart_8250_dma *dma = p->dma; > struct circ_buf *xmit = &p->port.state->xmit; > unsigned long flags; > + bool en_thri = false; > > dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr, > UART_XMIT_SIZE, DMA_TO_DEVICE); > @@ -40,11 +41,16 @@ static void __dma_tx_complete(void *param) > int ret; > > ret = serial8250_tx_dma(p); > - if (ret) { > - dma->tx_err = 1; > - p->ier |= UART_IER_THRI; > - serial_port_out(&p->port, UART_IER, p->ier); > - } > + if (ret) > + en_thri = true; > + > + } else if (p->capabilities & UART_CAP_RPM) > + en_thri = true; > + > + if (en_thri) { > + dma->tx_err = 1; > + p->ier |= UART_IER_THRI; > + serial_port_out(&p->port, UART_IER, p->ier); > } > > spin_unlock_irqrestore(&p->port.lock, flags); > -- > 2.1.0 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply index Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-09-10 19:29 [PATCH 00/16 v9] omap 8250 based uart + DMA Sebastian Andrzej Siewior 2014-09-10 19:29 ` [PATCH 01/16] tty: serial: 8250_core: allow to set ->throttle / ->unthrottle callbacks Sebastian Andrzej Siewior 2014-09-10 19:29 ` [PATCH 02/16] tty: serial: 8250_core: add run time pm Sebastian Andrzej Siewior 2014-09-29 9:46 ` Frans Klaver 2014-09-29 13:39 ` Sebastian Andrzej Siewior 2014-09-10 19:29 ` [PATCH 03/16] tty: serial: 8250_core: read only RX if there is something in the FIFO Sebastian Andrzej Siewior 2015-02-09 13:34 ` Nicolas Schichan 2015-02-09 23:34 ` Peter Hurley 2015-02-10 9:32 ` Sebastian Andrzej Siewior 2015-02-10 12:04 ` Nicolas Schichan 2015-02-10 17:46 ` Peter Hurley 2015-02-11 20:01 ` Peter Hurley 2015-02-11 20:03 ` Tony Lindgren 2015-02-11 20:42 ` Peter Hurley 2015-02-12 8:45 ` Sebastian Andrzej Siewior 2015-02-12 9:40 ` Russell King - ARM Linux 2015-02-12 16:32 ` Peter Hurley 2015-02-12 19:23 ` Sebastian Andrzej Siewior 2015-02-12 19:55 ` Peter Hurley 2015-02-12 20:34 ` Sebastian Andrzej Siewior 2015-02-13 18:51 ` Sebastian Andrzej Siewior 2015-02-13 23:15 ` Russell King - ARM Linux 2015-02-15 17:32 ` [PATCH] serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO" Sebastian Andrzej Siewior 2015-05-12 20:25 ` Tony Lindgren 2014-09-10 19:29 ` [PATCH 04/16] tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused() Sebastian Andrzej Siewior 2014-09-10 19:30 ` [PATCH 05/16] tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx() Sebastian Andrzej Siewior 2014-09-11 11:19 ` Heikki Krogerus 2014-09-10 19:30 ` [PATCH 06/16] tty: serial: Add 8250-core based omap driver Sebastian Andrzej Siewior 2014-09-11 11:57 ` Peter Hurley 2014-09-16 17:01 ` Sebastian Andrzej Siewior 2014-09-29 9:38 ` Frans Klaver 2014-09-29 13:27 ` Sebastian Andrzej Siewior 2014-09-29 13:34 ` Frans Klaver 2014-09-10 19:30 ` [PATCH 07/16] tty: serial: 8250_dma: handle error on TX submit Sebastian Andrzej Siewior 2014-09-10 19:30 ` [PATCH 08/16] tty: serial: 8250_dma: enqueue RX dma again on completion Sebastian Andrzej Siewior 2014-09-10 19:30 ` [PATCH 09/16] tty: serial: 8250_dma: Add a TX trigger workaround for AM33xx Sebastian Andrzej Siewior 2014-09-11 11:17 ` Heikki Krogerus 2014-09-11 11:42 ` Sebastian Andrzej Siewior 2014-09-11 12:32 ` Peter Hurley 2014-09-11 12:50 ` Sebastian Andrzej Siewior 2014-09-11 14:35 ` Peter Hurley 2014-09-15 17:01 ` Sebastian Andrzej Siewior 2014-09-16 16:55 ` Sebastian Andrzej Siewior 2014-09-17 12:20 ` Peter Hurley 2014-09-17 16:25 ` Sebastian Andrzej Siewior 2014-09-29 16:15 ` Sebastian Andrzej Siewior 2014-09-11 15:11 ` Frans Klaver 2014-09-11 16:04 ` Sebastian Andrzej Siewior 2014-09-11 17:04 ` Frans Klaver 2014-09-12 7:23 ` Sebastian Andrzej Siewior [not found] ` <20140912094010.GE28458@ci00147.xsens-tech.local> 2014-09-12 9:51 ` Sebastian Andrzej Siewior 2014-09-12 10:28 ` Frans Klaver 2014-09-15 16:42 ` Sebastian Andrzej Siewior 2014-09-16 9:05 ` Frans Klaver 2014-09-16 12:42 ` Frans Klaver 2014-09-16 14:23 ` Frans Klaver 2014-09-17 10:28 ` Frans Klaver 2014-09-21 20:41 ` Sebastian Andrzej Siewior 2014-09-22 9:28 ` Frans Klaver 2014-09-24 7:56 ` Sebastian Andrzej Siewior 2014-09-25 15:14 ` Sebastian Andrzej Siewior 2014-09-25 15:18 ` Frans Klaver 2014-09-29 8:50 ` Frans Klaver 2014-09-29 9:54 ` Sebastian Andrzej Siewior 2014-09-29 10:30 ` Frans Klaver 2014-09-30 8:44 ` Frans Klaver 2014-10-02 10:27 ` Sebastian Andrzej Siewior 2014-10-13 14:55 ` Frans Klaver 2014-09-23 17:03 ` Peter Hurley 2014-09-24 7:53 ` Sebastian Andrzej Siewior 2014-09-25 10:42 ` Sebastian Andrzej Siewior 2014-09-25 11:31 ` Peter Hurley 2014-09-25 13:11 ` Sebastian Andrzej Siewior 2014-09-17 16:34 ` Sebastian Andrzej Siewior 2014-09-19 10:22 ` Heikki Krogerus 2014-09-19 10:58 ` Sebastian Andrzej Siewior 2014-09-19 11:25 ` Peter Hurley 2014-09-22 7:46 ` Heikki Krogerus 2014-09-25 9:24 ` Sebastian Andrzej Siewior 2014-09-10 19:30 ` [PATCH 10/16] tty: serial: 8250_dma: optimize the xmit path due to UART_BUG_DMA_TX Sebastian Andrzej Siewior 2014-09-10 19:30 ` [PATCH 11/16] tty: serial: 8250_dma: keep own book keeping about RX transfers Sebastian Andrzej Siewior 2014-09-10 19:30 ` [PATCH 12/16] tty: serial: 8250_dma: handle the UART RDI event while DMA remains idle Sebastian Andrzej Siewior 2014-09-29 9:23 ` Frans Klaver 2014-09-10 19:30 ` [PATCH 13/16] tty: serial: 8250_dma: add pm runtime Sebastian Andrzej Siewior 2014-09-29 9:26 ` Frans Klaver [this message] 2014-09-29 9:56 ` Sebastian Andrzej Siewior 2014-09-10 19:30 ` [PATCH 14/16] arm: dts: am33xx: add DMA properties for UART Sebastian Andrzej Siewior 2014-09-10 19:30 ` [PATCH 15/16] arm: dts: dra7: " Sebastian Andrzej Siewior 2014-09-10 19:30 ` [PATCH 16/16] tty: serial: 8250: omap: add dma support Sebastian Andrzej Siewior 2014-09-12 22:43 ` [PATCH 00/16 v9] omap 8250 based uart + DMA Tony Lindgren 2014-09-15 11:50 ` Sebastian Andrzej Siewior 2014-09-16 12:57 ` Sebastian Andrzej Siewior 2014-09-16 16:48 ` Tony Lindgren 2014-09-16 21:30 ` Tony Lindgren 2014-09-17 8:38 ` Sebastian Andrzej Siewior 2014-09-17 9:05 ` Sebastian Andrzej Siewior 2014-09-26 16:02 ` Greg KH
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