Hi Prabhakark Thank you for the patch > Reorder the initialization sequence in `usbhs_probe()` to enable runtime > PM before accessing registers, preventing potential crashes due to > uninitialized clocks. > > Currently, in the probe path, registers are accessed before enabling the > clocks, leading to a synchronous external abort on the RZ/V2H SoC. > The problematic call flow is as follows: > > usbhs_probe() > usbhs_sys_clock_ctrl() > usbhs_bset() > usbhs_write() > iowrite16() <-- Register access before enabling clocks This patch itself is not so bad idea, but basically, we should not assume the power/clock was enabled since kernel boot. In this driver, register access happen only during power enable <-> power disable (except your issue case), and this is good idea. So, the strange is usbhs_sys_clock_ctrl() call in usbhs_probe() (without power enable) I guess. According to the comment, it is just caring boot loader, and usbhs_sys_clock_ctrl() itself will be called when usbhsc_power_ctrl() was called anyway. And more, if my understanding was correct, Renesas clock driver will stop all unused devices clock/power after boot. So maybe we can just remove strange usbhs_sys_clock_ctrl() from usbhs_probe() ? Thank you for your help !! Best regards --- Kuninori Morimoto
