Hi Lee, Can you help me with this question?
Thanks Lucas On Mon, Aug 5, 2019 at 2:43 PM Lucas Tanure <[email protected]> wrote: > > Hi, > > I would like to understand mfd_add_devices call and platform_data section. > An mfd device can have platform_data, which is kmemdup at > platform_device_add_data from platform_device_add_data call inside > mfd_add_device. And after this kmemdup the new mfd device receives the > clone memory and the pointer given to platform_device_add_data is freed. > > All the drivers I read the platform_data is static, which in my view can > not be freed and kfrees says: > > "Don't free memory not originally allocated by kmalloc() or you will run > into trouble." > > So, my questions is : Should my driver kmalloc platform_data first and then > call mfd_add_devices ? Or it's fine to give static memory to it ? > > Example driver: > > drivers/mfd/vexpress-sysreg.c: > > static struct syscon_platform_data vexpress_sysreg_sys_id_pdata = { > .label = "sys_id", > }; > > static struct mfd_cell vexpress_sysreg_cells[] = { > { > .name = "syscon", > .num_resources = 1, > .resources = (struct resource []) { > DEFINE_RES_MEM(SYS_ID, 0x4), > }, > .platform_data = &vexpress_sysreg_sys_id_pdata, > .pdata_size = sizeof(vexpress_sysreg_sys_id_pdata), > }, > > For this case mfd_add_devices will free vexpress_sysreg_sys_id_pdata, but > it's static. > > Thanks > Lucas
