On Mon, 18 Feb 2019 at 11:40, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote: > > Hi Krzysztof, > > On Mon, Feb 18, 2019 at 11:27 AM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote: > > The problem > > =========== > > Several device types (platform, amba, spi etc.) provide a driver_override > > field. On sysfs store or during device removal, they kfree() the > > existing value. > > > > However the users are unaware of this and set the driver_override like: > > > > pdev->driver_override = "exynos5-subcmu"; > > > > which obviously leads to error. > > IMHO driver_override is not meant to be set by a driver, only from userspace, > for binding the device to vfio (is there another use case?). > > > clk: samsung: exynos5: Fix kfree() of const memory on setting > > driver_override > > slimbus: ngd: Fix kfree() of const memory on setting driver_override > > I see all users set override immediately after allocating a platform device. > Can't they just allocate a platform device using the override name instead? > What am I missing? For the clk-exynos5-subcmu.c case, driver registers several sub-devices. Each sub-devices is a clock controller associated with power domain. I guess the author wanted to have meaningful names of these sub-devices (DISP, CAM etc. like names of power domains), instead of just exynos5-subcmu.1, exynos5-subcmu.2 ... If driver_override should not be used for such case, then I could replace it with what you said. For the other uses of driver_override (drivers/rpmsg/rpmsg_internal.h and drivers/slimbus/qcom-ngd-ctrl.c) I don't know. Best regards, Krzysztof