Hi Alan, > -----Original Message----- > From: Alan Stern <st...@rowland.harvard.edu> > Sent: Wednesday, January 09, 2019 23:14 > To: Ran Wang <ran.wan...@nxp.com> > Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>; linux- > u...@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: RE: [PATCH 2/3] usb: ehci: fsl: Update register accessing for > arm/arm64 platforms > > On Wed, 9 Jan 2019, Ran Wang wrote: > > > > Why do you change this writel() into iowrite32be() but leave other > > > instances of writel() unchanged? Was this a mistake? > > > > Yes, I didn't notice there are other writel() used in this file. > > However, as I know, on both powerpc and arm SoC, EHCI FSL IP's memory > > mapped register block is always Big-endian, so I'd like to replace all > > writel() with iowrite32be() in this file. Is it necessary? > > > > Or I just replace them with ehci_writel() and select > CONFIG_USB_EHCI_BIG_ENDIAN_MMIO? > > That should work okay. ehci_fsl_setup() sets ehci->big_endian_desc and > ehci->big_endian_mmio according to the platform data, so you just have > to make sure the platform data is initialized correctly. > OK, so I should not change writel() into iowrite32be() at that place you mentioned, and still using iowrite32be()/ioread32be() to replace clrsetbits_be32(), am I right?
Regards, Ran > Alan Stern
