The patch

spi: tegra20-slink: explicitly enable/disable clock

has been applied to the spi tree at

https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git

All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying to this mail.

Thanks, Mark

From 7001cab1dabc0b72b2b672ef58a90ab64f5e2343 Mon Sep 17 00:00:00 2001

From: Marcel Ziswiler marcel.ziswiler@toradex.com Date: Wed, 29 Aug 2018 08:47:57 +0200 Subject: [PATCH] spi: tegra20-slink: explicitly enable/disable clock

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 marcel.ziswiler@toradex.com Signed-off-by: Mark Brown broonie@kernel.org Cc: stable@vger.kernel.org --- 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 @@ static int tegra_slink_probe(struct platform_device *pdev) 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);