From: Michael Walle <michael@walle.cc> To: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Rob Herring <robh+dt@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Shawn Guo <shawnguo@kernel.org>, Li Yang <leoyang.li@nxp.com>, Jiri Slaby <jslaby@suse.com>, Peng Fan <peng.fan@nxp.com>, Vabhav Sharma <vabhav.sharma@nxp.com>, Michael Walle <michael@walle.cc> Subject: [PATCH v2 3/9] tty: serial: fsl_lpuart: handle EPROBE_DEFER for DMA Date: Fri, 21 Feb 2020 18:47:48 +0100 [thread overview] Message-ID: <20200221174754.5295-4-michael@walle.cc> (raw) In-Reply-To: <20200221174754.5295-1-michael@walle.cc> The DMA channel might not be available at the first probe time. This is esp. the case if the DMA controller has an IOMMU mapping. Use the new dma_request_chan() API and handle EPROBE_DEFER errors. Also reorder the code a bit, so that we don't prepare the whole UART just to determine that the DMA channel is not ready yet and we have to undo all the stuff. Try to map the DMA channels earlier. Signed-off-by: Michael Walle <michael@walle.cc> --- drivers/tty/serial/fsl_lpuart.c | 35 +++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index c31b8f3db6bf..fd9f60d0817a 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -2416,6 +2416,7 @@ static int lpuart_probe(struct platform_device *pdev) const struct lpuart_soc_data *sdata = of_id->data; struct device_node *np = pdev->dev.of_node; struct lpuart_port *sport; + struct dma_chan *dma_chan; struct resource *res; int ret; @@ -2483,6 +2484,26 @@ static int lpuart_probe(struct platform_device *pdev) } sport->port.line = ret; + dma_chan = dma_request_chan(sport->port.dev, "tx"); + if (PTR_ERR(dma_chan) == -EPROBE_DEFER) { + ret = -EPROBE_DEFER; + goto failed_request_tx_dma; + } else if (IS_ERR(dma_chan)) + dev_info(sport->port.dev, "DMA tx channel request failed, " + "operating without tx DMA\n"); + else + sport->dma_tx_chan = dma_chan; + + dma_chan = dma_request_chan(sport->port.dev, "rx"); + if (PTR_ERR(dma_chan) == -EPROBE_DEFER) { + ret = -EPROBE_DEFER; + goto failed_request_rx_dma; + } else if (IS_ERR(dma_chan)) + dev_info(sport->port.dev, "DMA rx channel request failed, " + "operating without rx DMA\n"); + else + sport->dma_rx_chan = dma_chan; + ret = lpuart_enable_clks(sport); if (ret) goto failed_clock_enable; @@ -2520,22 +2541,16 @@ static int lpuart_probe(struct platform_device *pdev) sport->port.rs485_config(&sport->port, &sport->port.rs485); - sport->dma_tx_chan = dma_request_slave_channel(sport->port.dev, "tx"); - if (!sport->dma_tx_chan) - dev_info(sport->port.dev, "DMA tx channel request failed, " - "operating without tx DMA\n"); - - sport->dma_rx_chan = dma_request_slave_channel(sport->port.dev, "rx"); - if (!sport->dma_rx_chan) - dev_info(sport->port.dev, "DMA rx channel request failed, " - "operating without rx DMA\n"); - return 0; failed_attach_port: failed_irq_request: lpuart_disable_clks(sport); failed_clock_enable: + dma_release_channel(sport->dma_rx_chan); +failed_request_rx_dma: + dma_release_channel(sport->dma_tx_chan); +failed_request_tx_dma: failed_out_of_range: if (sport->id_allocated) ida_simple_remove(&fsl_lpuart_ida, sport->port.line); -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Michael Walle <michael@walle.cc> To: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Mark Rutland <mark.rutland@arm.com>, Peng Fan <peng.fan@nxp.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Li Yang <leoyang.li@nxp.com>, Michael Walle <michael@walle.cc>, Rob Herring <robh+dt@kernel.org>, Vabhav Sharma <vabhav.sharma@nxp.com>, Jiri Slaby <jslaby@suse.com>, Shawn Guo <shawnguo@kernel.org> Subject: [PATCH v2 3/9] tty: serial: fsl_lpuart: handle EPROBE_DEFER for DMA Date: Fri, 21 Feb 2020 18:47:48 +0100 [thread overview] Message-ID: <20200221174754.5295-4-michael@walle.cc> (raw) In-Reply-To: <20200221174754.5295-1-michael@walle.cc> The DMA channel might not be available at the first probe time. This is esp. the case if the DMA controller has an IOMMU mapping. Use the new dma_request_chan() API and handle EPROBE_DEFER errors. Also reorder the code a bit, so that we don't prepare the whole UART just to determine that the DMA channel is not ready yet and we have to undo all the stuff. Try to map the DMA channels earlier. Signed-off-by: Michael Walle <michael@walle.cc> --- drivers/tty/serial/fsl_lpuart.c | 35 +++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index c31b8f3db6bf..fd9f60d0817a 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -2416,6 +2416,7 @@ static int lpuart_probe(struct platform_device *pdev) const struct lpuart_soc_data *sdata = of_id->data; struct device_node *np = pdev->dev.of_node; struct lpuart_port *sport; + struct dma_chan *dma_chan; struct resource *res; int ret; @@ -2483,6 +2484,26 @@ static int lpuart_probe(struct platform_device *pdev) } sport->port.line = ret; + dma_chan = dma_request_chan(sport->port.dev, "tx"); + if (PTR_ERR(dma_chan) == -EPROBE_DEFER) { + ret = -EPROBE_DEFER; + goto failed_request_tx_dma; + } else if (IS_ERR(dma_chan)) + dev_info(sport->port.dev, "DMA tx channel request failed, " + "operating without tx DMA\n"); + else + sport->dma_tx_chan = dma_chan; + + dma_chan = dma_request_chan(sport->port.dev, "rx"); + if (PTR_ERR(dma_chan) == -EPROBE_DEFER) { + ret = -EPROBE_DEFER; + goto failed_request_rx_dma; + } else if (IS_ERR(dma_chan)) + dev_info(sport->port.dev, "DMA rx channel request failed, " + "operating without rx DMA\n"); + else + sport->dma_rx_chan = dma_chan; + ret = lpuart_enable_clks(sport); if (ret) goto failed_clock_enable; @@ -2520,22 +2541,16 @@ static int lpuart_probe(struct platform_device *pdev) sport->port.rs485_config(&sport->port, &sport->port.rs485); - sport->dma_tx_chan = dma_request_slave_channel(sport->port.dev, "tx"); - if (!sport->dma_tx_chan) - dev_info(sport->port.dev, "DMA tx channel request failed, " - "operating without tx DMA\n"); - - sport->dma_rx_chan = dma_request_slave_channel(sport->port.dev, "rx"); - if (!sport->dma_rx_chan) - dev_info(sport->port.dev, "DMA rx channel request failed, " - "operating without rx DMA\n"); - return 0; failed_attach_port: failed_irq_request: lpuart_disable_clks(sport); failed_clock_enable: + dma_release_channel(sport->dma_rx_chan); +failed_request_rx_dma: + dma_release_channel(sport->dma_tx_chan); +failed_request_tx_dma: failed_out_of_range: if (sport->id_allocated) ida_simple_remove(&fsl_lpuart_ida, sport->port.line); -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-02-21 17:48 UTC|newest] Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-21 17:47 [PATCH v2 0/9] tty: serial: fsl_lpuart various fixes and LS1028A support Michael Walle 2020-02-21 17:47 ` Michael Walle 2020-02-21 17:47 ` [PATCH v2 1/9] Revert "tty: serial: fsl_lpuart: drop EARLYCON_DECLARE" Michael Walle 2020-02-21 17:47 ` Michael Walle 2020-02-21 17:47 ` [PATCH v2 2/9] tty: serial: fsl_lpuart: free IDs allocated by IDA Michael Walle 2020-02-21 17:47 ` Michael Walle 2020-02-21 17:47 ` Michael Walle [this message] 2020-02-21 17:47 ` [PATCH v2 3/9] tty: serial: fsl_lpuart: handle EPROBE_DEFER for DMA Michael Walle 2020-02-27 22:34 ` Rob Herring 2020-02-27 22:34 ` Rob Herring 2020-02-27 22:48 ` Li Yang 2020-02-27 22:48 ` Li Yang 2020-02-27 23:03 ` Rob Herring 2020-02-27 23:03 ` Rob Herring 2020-02-28 11:46 ` Michael Walle 2020-02-28 11:46 ` Michael Walle 2020-02-28 21:50 ` Michael Walle 2020-02-28 21:50 ` Michael Walle 2020-02-28 21:53 ` Li Yang 2020-02-28 21:53 ` Li Yang 2020-02-21 17:47 ` [PATCH v2 4/9] tty: serial: fsl_lpuart: fix DMA mapping Michael Walle 2020-02-21 17:47 ` Michael Walle 2020-02-21 17:47 ` [PATCH v2 5/9] dt-bindings: serial: lpuart: add ls1028a compatibility Michael Walle 2020-02-21 17:47 ` Michael Walle 2020-02-26 21:37 ` Rob Herring 2020-02-26 21:37 ` Rob Herring 2020-02-21 17:47 ` [PATCH v2 6/9] tty: serial: fsl_lpuart: add LS1028A support Michael Walle 2020-02-21 17:47 ` Michael Walle 2020-02-21 17:47 ` [PATCH v2 7/9] tty: serial: fsl_lpuart: add LS1028A earlycon support Michael Walle 2020-02-21 17:47 ` Michael Walle 2020-02-21 17:47 ` [PATCH v2 8/9] arm64: dts: ls1028a: add "fsl,vf610-edma" compatible Michael Walle 2020-02-21 17:47 ` Michael Walle 2020-02-21 17:47 ` [PATCH v2 9/9] arm64: dts: ls1028a: add missing LPUART nodes Michael Walle 2020-02-21 17:47 ` Michael Walle
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