Re: [RFC PATCH 1/5] serial: arc: Remove __init marking from early write

2017-07-17 Thread Greg KH
On Tue, Jul 18, 2017 at 12:29:59PM +0800, Jeffy Chen wrote: > The earlycon would be alive outside the init code in these cases: > 1/ we have keep_bootcon in cmdline. > 2/ we don't have a real console to switch to. > > So remove the __init marking to avoid invalid memory access. > >

[RFC PATCH 0/5] earlycon hang under some conditions

2017-07-17 Thread Jeffy Chen
I was testing earlycon with 8250 dw serial console. And it hangs in these cases: 1/ kernel hang when calling early write function after free_initmem: a) the earlycon not disabled after the init code(due to keep_bootcon or not specify a real console to switch to) b) the early write func is

[RFC PATCH 1/5] serial: arc: Remove __init marking from early write

2017-07-17 Thread Jeffy Chen
The earlycon would be alive outside the init code in these cases: 1/ we have keep_bootcon in cmdline. 2/ we don't have a real console to switch to. So remove the __init marking to avoid invalid memory access. Signed-off-by: Jeffy Chen ---

Re: [PATCH 3/3 v8] ARC: hsdk: initial port for HSDK board

2017-07-17 Thread Rob Herring
On Wed, Jul 12, 2017 at 12:40:23PM +0300, Eugeniy Paltsev wrote: > From: Alexey Brodkin > > This initial port adds support of ARC HS Development Kit board with some > basic features such serial port, USB, SD/MMC and Ethernet. > > Essentially we run Linux kernel on all 4

Re: semantics of dma_map_single()

2017-07-17 Thread James Bottomley
On Mon, 2017-07-17 at 09:06 -0700, Vineet Gupta wrote: > Hi Christoph, > > On 07/16/2017 11:42 PM, Christoph Hellwig wrote: > > > > I would expect that it would support any contiguous range in > > the kernel mapping (e.g. no vmalloc and friends).  But it's not > > documented anywhere, and if no

Re: semantics of dma_map_single()

2017-07-17 Thread Vineet Gupta
Hi Christoph, On 07/16/2017 11:42 PM, Christoph Hellwig wrote: I would expect that it would support any contiguous range in the kernel mapping (e.g. no vmalloc and friends). But it's not documented anywhere, and if no in kernel users makes use of that fact at the moment it might be better to

Re: semantics of dma_map_single()

2017-07-17 Thread Christoph Hellwig
I would expect that it would support any contiguous range in the kernel mapping (e.g. no vmalloc and friends). But it's not documented anywhere, and if no in kernel users makes use of that fact at the moment it might be better to document a page size limitation and add asserts to enforce it.