On 20 June 2018 at 13:38, Andrzej Hajda <a.hajda@xxxxxxxxxxx> wrote: > Hi Krzysztof, > > On 20.06.2018 12:40, Krzysztof Kozlowski wrote: >> On 15 June 2018 at 14:26, Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> wrote: >>> Platform devices instantiated from device-tree always have pdev->id set to >>> -1, so use of_get_alias_id() helper to retrieve proper device id. >>> >>> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> >>> --- >>> drivers/gpu/drm/exynos/exynos_drm_gsc.c | 9 +++++++-- >>> 1 file changed, 7 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gsc.c b/drivers/gpu/drm/exynos/exynos_drm_gsc.c >>> index e99dd1e4ba65..a63287597985 100644 >>> --- a/drivers/gpu/drm/exynos/exynos_drm_gsc.c >>> +++ b/drivers/gpu/drm/exynos/exynos_drm_gsc.c >>> @@ -1196,7 +1196,12 @@ static int gsc_probe(struct platform_device *pdev) >>> struct exynos_drm_ipp_formats *formats; >>> struct gsc_context *ctx; >>> struct resource *res; >>> - int ret, i; >>> + int ret, i, id; >>> + >>> + ret = of_alias_get_id(pdev->dev.of_node, "gsc"); >>> + if (ret < 0) >>> + return ret; >>> + id = ret; >>> >>> ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL); >>> if (!ctx) >>> @@ -1254,7 +1259,7 @@ static int gsc_probe(struct platform_device *pdev) >>> } >>> >>> /* context initailization */ >>> - ctx->id = pdev->id; >>> + ctx->id = id; >> Why do you need ctx->id at all? I see it is used only in dev_dbg and >> dev_err messages but these should be easily identifiable by device >> name+address. Maybe get rid of ctx->id entirely? > > I am working on patches adding framebuffer display pre-processing > on-the-fly, they requires gscaler id to program sysreg registers. I hope > to post it in near future. OK, makes sense. Then I have a dependent comment - if alias id is used by driver then probably it should be validated to prevent errors like out-of-bounds access. DTB theoretically might come from out-of-tree or from older version. Something like this was reported for our pinctrl driver: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=93b0beae721b3344923b4b8317e9d83b542f4ca6 Probably the validation should come with your code, Andrzej. Not here. Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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