Re: [PATCH] usb: dwc2: fix regression on big-endian PowerPC/ARM systems

2016-05-12 Thread Arnd Bergmann
On Thursday 12 May 2016 14:43:43 Felipe Balbi wrote: > >> How many more drivers will we have to 'fix' like this ? > > > > Endianess problems will keep coming up, and we have hundreds or thousands > > of drivers that are written with a particular design in mind that could > > be wrong as soon as som

Re: [PATCH] usb: dwc2: fix regression on big-endian PowerPC/ARM systems

2016-05-12 Thread Felipe Balbi
Hi, (Arnd, you didn't Cc dwc2's maintainer. I'm also not part of TI anymore) Arnd Bergmann writes: > On Thursday 12 May 2016 14:25:49 Felipe Balbi wrote: >> > { >> > u32 value = __raw_readl(addr); >> > >> > - /* In order to preserve endianness __raw_* operation is used. >> > There

Re: [PATCH] usb: dwc2: fix regression on big-endian PowerPC/ARM systems

2016-05-12 Thread Arnd Bergmann
On Thursday 12 May 2016 14:25:49 Felipe Balbi wrote: > > { > > u32 value = __raw_readl(addr); > > > > - /* In order to preserve endianness __raw_* operation is used. > > Therefore > > - * a barrier is needed to ensure IO access is not re-ordered across > > + /* in order to pr

Re: [PATCH] usb: dwc2: fix regression on big-endian PowerPC/ARM systems

2016-05-12 Thread Felipe Balbi
Hi, Arnd Bergmann writes: > A patch that went into Linux-4.4 to fix big-endian mode on a Lantiq > MIPS system unfortunately broke big-endian operation on PowerPC > APM82181 as reported by Christian Lamparter, and likely other > systems. > > It actually introduced multiple issues: > > - it broke

[PATCH] usb: dwc2: fix regression on big-endian PowerPC/ARM systems

2016-05-12 Thread Arnd Bergmann
A patch that went into Linux-4.4 to fix big-endian mode on a Lantiq MIPS system unfortunately broke big-endian operation on PowerPC APM82181 as reported by Christian Lamparter, and likely other systems. It actually introduced multiple issues: - it broke big-endian ARM kernels: any machine that wa