-----Original Message----- From: Marek Vasut marex@denx.de Sent: Wednesday, 21 June, 2023 10:19 PM To: Lim, Jit Loon jit.loon.lim@intel.com; u-boot@lists.denx.de Cc: Jagan Teki jagan@amarulasolutions.com; Simon simon.k.r.goldschmidt@gmail.com; Chee, Tien Fong tien.fong.chee@intel.com; Hea, Kok Kiang kok.kiang.hea@intel.com; Lokanathan, Raaj raaj.lokanathan@intel.com; Maniyam, Dinesh dinesh.maniyam@intel.com; Ng, Boon Khai boon.khai.ng@intel.com; Yuslaimi, Alif Zakuan alif.zakuan.yuslaimi@intel.com; Chong, Teik Heng teik.heng.chong@intel.com; Zamri, Muhammad Hazim Izzat muhammad.hazim.izzat.zamri@intel.com; Tang, Sieu Mun sieu.mun.tang@intel.com; Bin Meng bmeng.cn@gmail.com Subject: Re: [PATCH v1] HSD #18028953892: usb: xhci-dwc3: Fix USB3.1 controller register access in reset state
On 6/21/23 16:11, Jit Loon Lim wrote:
From: Teik Heng Chong teik.heng.chong@intel.com
The controller registers should not be accessed while the controller's vcc_reset_n is asserted.
Signed-off-by: Teik Heng Chong teik.heng.chong@intel.com
Is this patch ported from Linux or is this custom development ?
Is there a matching patch/fix in Linux already ?
In xhci_dwc3_probe(), the program sequence is vcc reset -> clk init -> phy setup -> xhci_register therefore, when xhci_dwc3_remove is called, the proper usb stop sequence should be xhci_register _> phy setup -> clk init -> vcc reset
if we look at linux driver https://elixir.bootlin.com/linux/latest/source/drivers/usb/dwc3/dwc3-of-simp...
dwc3_of_simple_probe: The sequence is reset -> clock __dwc3_of_simple_teardown: Then, clock -> reset
So based on the above, we have made changes and the uboot fix is now aligned with linux driver.