I had Kernel 3.19.0 (originally from https://github.com/raspberrypi/linux/tree/rpi-3.19.y – now updated) running on my Pi (armv6) and Pi2 (armv7) with no problems (apart from the Pi2 seeming very sluggish..) but after that had a few ‘issues’..

Pi:  Kernel 3.19.1 OK, but 3.19.2 refused to boot (nothing on console)

Pi2:  Kernel 3.19.1 booted and then crashed:

BCM2708FB: allocated DMA memory 47c00000
BCM2708FB: allocated DMA channel 0 @ f3007000
------------[ cut here ]------------
Kernel BUG at 802a04ec [verbose debug info unavailable]
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.19.1-v7 #1
Hardware name: BCM2709
task: 87040000 ti: 87048000 task.ti: 87048000
PC is at bcm2708_fb_set_par+0x120/0x124
LR is at console_unlock+0x2e0/0x4f4
pc : [<802a04ec>] lr : [<8005d488>] psr: 60000113
sp : 87049d70 ip : 87049d10 fp : 87049d94
r10: 00000102 r9 : 00000010 r8 : 00000268
r7 : 8727003c r6 : 87049d74 r5 : 87c10000 r4 : 87270000
r3 : 00000000 r2 : 00000000 r1 : 60000113 r0 : 806410f0
Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
......... etc  etc..........

Pi2 with Kernel 3.19.2 had the same result as the Pi – no boot, and blank console..

It seems that the git repository contents are often updated, but the version is still the same, which makes tracking updates tricky!     This means that the ‘3.19.2’ I download today may well be different from the ‘3.19.2’ I downloaded a few days ago..   I know that this can all be controlled by git, but it it might be better for the average user if the ‘extraversion’ was used to signify fix levels, without resorting to git command complexity to control all this..

Robert Gadsdon.    March 23, 2015