From a2b9280113522c7a7608c02933bc66da3e87da84 Mon Sep 17 00:00:00 2001 From: Marcel Ziswiler Date: Wed, 29 Aug 2018 08:47:57 +0200 Subject: [PATCH] spi: tegra20-slink: explicitly enable/disable clock commit 7001cab1dabc0b72b2b672ef58a90ab64f5e2343 upstream. Depending on the SPI instance one may get an interrupt storm upon requesting resp. interrupt unless the clock is explicitly enabled beforehand. This has been observed trying to bring up instance 4 on T20. Signed-off-by: Marcel Ziswiler Signed-off-by: Mark Brown Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-tegra20-slink.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi-tegra20-slink.c b/drivers/spi/spi-tegra20-slink.c index 6f7b946b5ced..1427f343b39a 100644 --- a/drivers/spi/spi-tegra20-slink.c +++ b/drivers/spi/spi-tegra20-slink.c @@ -1063,6 +1063,24 @@ static int tegra_slink_probe(struct platform_device *pdev) goto exit_free_master; } + /* disabled clock may cause interrupt storm upon request */ + tspi->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(tspi->clk)) { + ret = PTR_ERR(tspi->clk); + dev_err(&pdev->dev, "Can not get clock %d\n", ret); + goto exit_free_master; + } + ret = clk_prepare(tspi->clk); + if (ret < 0) { + dev_err(&pdev->dev, "Clock prepare failed %d\n", ret); + goto exit_free_master; + } + ret = clk_enable(tspi->clk); + if (ret < 0) { + dev_err(&pdev->dev, "Clock enable failed %d\n", ret); + goto exit_free_master; + } + spi_irq = platform_get_irq(pdev, 0); tspi->irq = spi_irq; ret = request_threaded_irq(tspi->irq, tegra_slink_isr, @@ -1071,14 +1089,7 @@ static int tegra_slink_probe(struct platform_device *pdev) if (ret < 0) { dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n", tspi->irq); - goto exit_free_master; - } - - tspi->clk = devm_clk_get(&pdev->dev, NULL); - if (IS_ERR(tspi->clk)) { - dev_err(&pdev->dev, "can not get clock\n"); - ret = PTR_ERR(tspi->clk); - goto exit_free_irq; + goto exit_clk_disable; } tspi->rst = devm_reset_control_get_exclusive(&pdev->dev, "spi"); @@ -1138,6 +1149,8 @@ exit_rx_dma_free: tegra_slink_deinit_dma_param(tspi, true); exit_free_irq: free_irq(spi_irq, tspi); +exit_clk_disable: + clk_disable(tspi->clk); exit_free_master: spi_master_put(master); return ret; @@ -1150,6 +1163,8 @@ static int tegra_slink_remove(struct platform_device *pdev) free_irq(tspi->irq, tspi); + clk_disable(tspi->clk); + if (tspi->tx_dma_chan) tegra_slink_deinit_dma_param(tspi, false); -- 2.11.0