Re: [PATCH 2/4] spi: mt7621: Use the devm_clk_get_enabled() helper to simplify error handling
From: Matthias Brugger <matthias.bgg@gmail.com>
Date: 2022-08-29 11:28:16
Also in:
kernel-janitors, linux-mediatek, linux-spi, lkml
On 27/08/2022 13:42, Christophe JAILLET wrote:
The devm_clk_get_enabled() helper:
- calls devm_clk_get()
- calls clk_prepare_enable() and registers what is needed in order to
call clk_disable_unprepare() when needed, as a managed resource.
This helper is well suited for cases where the clock would be kept
prepared or enabled for the whole lifetime of the driver.
This simplifies the error handling a lot.
The order between spi_unregister_controller() (in the remove function) and
the clk_disable_unprepare() (now handle by a managed resource) is kept
the same.
(see commit 46b5c4fb87ce ("spi: mt7621: Don't leak SPI master in probe
error path") to see why it matters)
Signed-off-by: Christophe JAILLET <redacted>Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
quoted hunk ↗ jump to hunk
--- The order with devm_spi_release_controller() (which undoes devm_spi_alloc_master()) is reversed, but I don't think it is an issue. --- drivers/spi/spi-mt7621.c | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-)diff --git a/drivers/spi/spi-mt7621.c b/drivers/spi/spi-mt7621.c index 351b0ef52bbc..2580b28042be 100644 --- a/drivers/spi/spi-mt7621.c +++ b/drivers/spi/spi-mt7621.c@@ -327,7 +327,6 @@ static int mt7621_spi_probe(struct platform_device *pdev) struct spi_controller *master; struct mt7621_spi *rs; void __iomem *base; - int status = 0; struct clk *clk; int ret;@@ -339,19 +338,14 @@ static int mt7621_spi_probe(struct platform_device *pdev) if (IS_ERR(base)) return PTR_ERR(base); - clk = devm_clk_get(&pdev->dev, NULL); + clk = devm_clk_get_enabled(&pdev->dev, NULL); if (IS_ERR(clk)) return dev_err_probe(&pdev->dev, PTR_ERR(clk), "unable to get SYS clock\n"); - status = clk_prepare_enable(clk); - if (status) - return status; - master = devm_spi_alloc_master(&pdev->dev, sizeof(*rs)); if (!master) { dev_info(&pdev->dev, "master allocation failed\n"); - clk_disable_unprepare(clk); return -ENOMEM; }@@ -376,13 +370,10 @@ static int mt7621_spi_probe(struct platform_device *pdev) ret = device_reset(&pdev->dev); if (ret) { dev_err(&pdev->dev, "SPI reset failed!\n"); - clk_disable_unprepare(clk); return ret; } ret = spi_register_controller(master); - if (ret) - clk_disable_unprepare(clk); return ret; }@@ -390,13 +381,10 @@ static int mt7621_spi_probe(struct platform_device *pdev) static int mt7621_spi_remove(struct platform_device *pdev) { struct spi_controller *master; - struct mt7621_spi *rs; master = dev_get_drvdata(&pdev->dev); - rs = spi_controller_get_devdata(master); spi_unregister_controller(master); - clk_disable_unprepare(rs->clk); return 0; }
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