[PATCH] drm/i915: cope with large i2c transfers

2015-04-21 Thread Linus Torvalds
On Tue, Apr 21, 2015 at 12:24 AM, Chris Wilson wrote: > > Though I am tempted to say we should impose the 256 byte limit for > stable@ If the docs say 256, I'd suggest using that not just for stable, but for anything. Maybe 511 bytes work everywhere and the docs are just wrong. And maybe it does

[PATCH] drm/i915: cope with large i2c transfers

2015-04-21 Thread Chris Wilson
On Mon, Apr 20, 2015 at 03:11:16PM -0700, Dmitry Torokhov wrote: > The hardware is limited to 2^9 - 1 (511) bytes transfers, and current > driver has no protections in case users attempt to do larger transfers. > The code will just stomp over status register and mayhem ensues. Interesting. The spe

[PATCH] drm/i915: cope with large i2c transfers

2015-04-20 Thread Dmitry Torokhov
The hardware is limited to 2^9 - 1 (511) bytes transfers, and current driver has no protections in case users attempt to do larger transfers. The code will just stomp over status register and mayhem ensues. Let's split larger transfers into digestable chunks. Doing this allows Atmel MXT driver on