From: Vignesh Raghavendra <vigneshr@xxxxxx> [ Upstream commit 32f2fc5dc3992b4b60cc6b1a6a31be605cc9c3a2 ] dma_request_channel() can return -EPROBE_DEFER, if DMA driver is not ready. Currently driver just falls back to PIO mode on probe deferral. Fix this by requesting all required channels during probe and propagating EPROBE_DEFER error code. Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx> Link: https://lore.kernel.org/r/20200204124816.16735-3-vigneshr@xxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/spi/spi-omap2-mcspi.c | 77 ++++++++++++++++++++---------------------- 1 file changed, 38 insertions(+), 39 deletions(-) --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -974,20 +974,12 @@ static int omap2_mcspi_setup_transfer(st * Note that we currently allow DMA only if we get a channel * for both rx and tx. Otherwise we'll do PIO for both rx and tx. */ -static int omap2_mcspi_request_dma(struct spi_device *spi) +static int omap2_mcspi_request_dma(struct omap2_mcspi *mcspi, + struct omap2_mcspi_dma *mcspi_dma) { - struct spi_master *master = spi->master; - struct omap2_mcspi *mcspi; - struct omap2_mcspi_dma *mcspi_dma; int ret = 0; - mcspi = spi_master_get_devdata(master); - mcspi_dma = mcspi->dma_channels + spi->chip_select; - - init_completion(&mcspi_dma->dma_rx_completion); - init_completion(&mcspi_dma->dma_tx_completion); - - mcspi_dma->dma_rx = dma_request_chan(&master->dev, + mcspi_dma->dma_rx = dma_request_chan(mcspi->dev, mcspi_dma->dma_rx_ch_name); if (IS_ERR(mcspi_dma->dma_rx)) { ret = PTR_ERR(mcspi_dma->dma_rx); @@ -995,7 +987,7 @@ static int omap2_mcspi_request_dma(struc goto no_dma; } - mcspi_dma->dma_tx = dma_request_chan(&master->dev, + mcspi_dma->dma_tx = dma_request_chan(mcspi->dev, mcspi_dma->dma_tx_ch_name); if (IS_ERR(mcspi_dma->dma_tx)) { ret = PTR_ERR(mcspi_dma->dma_tx); @@ -1004,20 +996,40 @@ static int omap2_mcspi_request_dma(struc mcspi_dma->dma_rx = NULL; } + init_completion(&mcspi_dma->dma_rx_completion); + init_completion(&mcspi_dma->dma_tx_completion); + no_dma: return ret; } +static void omap2_mcspi_release_dma(struct spi_master *master) +{ + struct omap2_mcspi *mcspi = spi_master_get_devdata(master); + struct omap2_mcspi_dma *mcspi_dma; + int i; + + for (i = 0; i < master->num_chipselect; i++) { + mcspi_dma = &mcspi->dma_channels[i]; + + if (mcspi_dma->dma_rx) { + dma_release_channel(mcspi_dma->dma_rx); + mcspi_dma->dma_rx = NULL; + } + if (mcspi_dma->dma_tx) { + dma_release_channel(mcspi_dma->dma_tx); + mcspi_dma->dma_tx = NULL; + } + } +} + static int omap2_mcspi_setup(struct spi_device *spi) { int ret; struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); struct omap2_mcspi_regs *ctx = &mcspi->ctx; - struct omap2_mcspi_dma *mcspi_dma; struct omap2_mcspi_cs *cs = spi->controller_state; - mcspi_dma = &mcspi->dma_channels[spi->chip_select]; - if (!cs) { cs = kzalloc(sizeof *cs, GFP_KERNEL); if (!cs) @@ -1042,13 +1054,6 @@ static int omap2_mcspi_setup(struct spi_ } } - if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) { - ret = omap2_mcspi_request_dma(spi); - if (ret) - dev_warn(&spi->dev, "not using DMA for McSPI (%d)\n", - ret); - } - ret = pm_runtime_get_sync(mcspi->dev); if (ret < 0) { pm_runtime_put_noidle(mcspi->dev); @@ -1065,12 +1070,8 @@ static int omap2_mcspi_setup(struct spi_ static void omap2_mcspi_cleanup(struct spi_device *spi) { - struct omap2_mcspi *mcspi; - struct omap2_mcspi_dma *mcspi_dma; struct omap2_mcspi_cs *cs; - mcspi = spi_master_get_devdata(spi->master); - if (spi->controller_state) { /* Unlink controller state from context save list */ cs = spi->controller_state; @@ -1079,19 +1080,6 @@ static void omap2_mcspi_cleanup(struct s kfree(cs); } - if (spi->chip_select < spi->master->num_chipselect) { - mcspi_dma = &mcspi->dma_channels[spi->chip_select]; - - if (mcspi_dma->dma_rx) { - dma_release_channel(mcspi_dma->dma_rx); - mcspi_dma->dma_rx = NULL; - } - if (mcspi_dma->dma_tx) { - dma_release_channel(mcspi_dma->dma_tx); - mcspi_dma->dma_tx = NULL; - } - } - if (gpio_is_valid(spi->cs_gpio)) gpio_free(spi->cs_gpio); } @@ -1302,6 +1290,9 @@ static bool omap2_mcspi_can_dma(struct s if (spi_controller_is_slave(master)) return true; + master->dma_rx = mcspi_dma->dma_rx; + master->dma_tx = mcspi_dma->dma_tx; + return (xfer->len >= DMA_MIN_BYTES); } @@ -1464,6 +1455,11 @@ static int omap2_mcspi_probe(struct plat for (i = 0; i < master->num_chipselect; i++) { sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i); sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i); + + status = omap2_mcspi_request_dma(mcspi, + &mcspi->dma_channels[i]); + if (status == -EPROBE_DEFER) + goto free_master; } status = platform_get_irq(pdev, 0); @@ -1501,6 +1497,7 @@ disable_pm: pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); free_master: + omap2_mcspi_release_dma(master); spi_master_put(master); return status; } @@ -1510,6 +1507,8 @@ static int omap2_mcspi_remove(struct pla struct spi_master *master = platform_get_drvdata(pdev); struct omap2_mcspi *mcspi = spi_master_get_devdata(master); + omap2_mcspi_release_dma(master); + pm_runtime_dont_use_autosuspend(mcspi->dev); pm_runtime_put_sync(mcspi->dev); pm_runtime_disable(&pdev->dev);
