| Message ID | 20240425075628.838497-1-m.szyprowski@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | clk: samsung: Revert "clk: Use device_get_match_data()" | expand |
On 25/04/2024 09:56, Marek Szyprowski wrote: > device_get_match_data() function should not be used on the device other > than the one matched to the given driver, because it always returns the > match_data of the matched driver. In case of exynos-clkout driver, the > original code matches the OF IDs on the PARENT device, so replacing it > with of_device_get_match_data() broke the driver. > > This has been already pointed once in commit 2bc5febd05ab ("clk: samsung: > Revert "clk: samsung: exynos-clkout: Use of_device_get_match_data()""). > To avoid further confusion, add a comment about this special case, which > requires direct of_match_device() call to pass custom IDs array. > > This partially reverts commit 409c39ec92a35e3708f5b5798c78eae78512cd71. D'oh! Again! But to be honest, I think there misleading code is that exynos-clkout (so the child) has: .of_match_table = exynos_clkout_ids, So one really can believe that this driver matches to exynos_clkout_ids, which are the same as exynos-pmu (parent). I think we should drop the of_match_table and rely on driver name matching (MFD cell) or platform_device_id. This patch is correct, so above solution could be added as 2 patch. Thanks for noticing it. Best regards, Krzysztof
On Thu, 25 Apr 2024 09:56:28 +0200, Marek Szyprowski wrote: > device_get_match_data() function should not be used on the device other > than the one matched to the given driver, because it always returns the > match_data of the matched driver. In case of exynos-clkout driver, the > original code matches the OF IDs on the PARENT device, so replacing it > with of_device_get_match_data() broke the driver. > > This has been already pointed once in commit 2bc5febd05ab ("clk: samsung: > Revert "clk: samsung: exynos-clkout: Use of_device_get_match_data()""). > To avoid further confusion, add a comment about this special case, which > requires direct of_match_device() call to pass custom IDs array. > > [...] Applied, thanks! [1/1] clk: samsung: Revert "clk: Use device_get_match_data()" https://git.kernel.org/krzk/linux/c/da244c16ac58a3b1b7d8c54ec7780fd8326da2ff Best regards,
diff --git a/drivers/clk/samsung/clk-exynos-clkout.c b/drivers/clk/samsung/clk-exynos-clkout.c index 3484e6cc80ad..503c6f5b20d5 100644 --- a/drivers/clk/samsung/clk-exynos-clkout.c +++ b/drivers/clk/samsung/clk-exynos-clkout.c @@ -13,9 +13,9 @@ #include <linux/io.h> #include <linux/of.h> #include <linux/of_address.h> +#include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pm.h> -#include <linux/property.h> #define EXYNOS_CLKOUT_NR_CLKS 1 #define EXYNOS_CLKOUT_PARENTS 32 @@ -84,17 +84,24 @@ MODULE_DEVICE_TABLE(of, exynos_clkout_ids); static int exynos_clkout_match_parent_dev(struct device *dev, u32 *mux_mask) { const struct exynos_clkout_variant *variant; + const struct of_device_id *match; if (!dev->parent) { dev_err(dev, "not instantiated from MFD\n"); return -EINVAL; } - variant = device_get_match_data(dev->parent); - if (!variant) { + /* + * 'exynos_clkout_ids' arrays is not the ids array matched by + * the dev->parent driver, so of_device_get_match_data() or + * device_get_match_data() cannot be used here. + */ + match = of_match_device(exynos_clkout_ids, dev->parent); + if (!match) { dev_err(dev, "cannot match parent device\n"); return -EINVAL; } + variant = match->data; *mux_mask = variant->mux_mask;
device_get_match_data() function should not be used on the device other than the one matched to the given driver, because it always returns the match_data of the matched driver. In case of exynos-clkout driver, the original code matches the OF IDs on the PARENT device, so replacing it with of_device_get_match_data() broke the driver. This has been already pointed once in commit 2bc5febd05ab ("clk: samsung: Revert "clk: samsung: exynos-clkout: Use of_device_get_match_data()""). To avoid further confusion, add a comment about this special case, which requires direct of_match_device() call to pass custom IDs array. This partially reverts commit 409c39ec92a35e3708f5b5798c78eae78512cd71. Fixes: 409c39ec92a3 ("clk: Use device_get_match_data()") Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- drivers/clk/samsung/clk-exynos-clkout.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)