[Linux-exynos] general comments

Merlijn Wajer merlijn at wizzup.org
Thu Feb 26 12:23:21 CET 2015


Hi Bruce,

Please send me your preferred username and email, so I can give you a
wiki account. Then you can modify the wiki yourself.

Cheers,
Merlijn

On 24/02/15 18:02, bruce m beach wrote:
> Hi Merlijn
> 
> 
>>> Sound and wi-fi are not currently working for me
>> Sound is still in the works (but looks like it is getting some progress
>> in the last few days), and it looks like wifi was broken by something
>> trivial, so that should also work again in a bit.
> 
> Both of these I'm not particularly anxious for, and can wait
> indefinitely, Wifi I am interested in because I roll my own
> system and this time around I am not using udev and as far
> as I can tell it is being phased out. I could go on about
> this but what I really want to say is to point out the
> following particularly interesting kernel parameter:
> 
>> device Drivers > Generic Driver Options
> 
> [*] Support for uevent helper
> 
> and the help message for it
> 
> CONFIG_UEVENT_HELPER:
> 
> The uevent helper program is forked by the kernel for every
> uevent. Before the switch to the netlink-based uevent
> source, this was used to hook hotplug scripts into kernel
> device events. It usually pointed to a shell script at
> /sbin/hotplug.
> 
>  ==> This should not be used today, <== because usual systems create
> many events at bootup or device discovery in a very short
> time frame. One forked process per event can create so many
> processes that it creates a high system load, or on smaller
> systems it is known to create out-of-memory situations
> during bootup.
> 
> I disabled it but exynos_defconfig enables it. Also I built
> /sd8797_uapsta.bin right into the kernel itself with the
> following from dmesg
> 
> [    7.321724] bus: 'sdio': add driver mwifiex_sdio
> [    9.818780] bus: 'sdio': driver_probe_device: matched
>                device mmc2:0001:1 with driver mwifiex_sdio
> [    9.818785] bus: 'sdio': really_probe: probing driver
>                mwifiex_sdio with device mmc2:0001:1
> [    9.818802] mwifiex_sdio mmc2:0001:1: no default pinctrl
>                state
> [    9.819318] mwifiex: rx work enabled, cpus 2
> [    9.819605] driver: 'mwifiex_sdio': driver_bound: bound
>                to device 'mmc2:0001:1'
> [    9.819616] bus: 'sdio': really_probe: bound device
>                mmc2:0001:1 to driver mwifiex_sdio
> [    9.820001] __allocate_fw_buf: fw-mrvl/sd8797_uapsta.bin
>                buf=ed943a00
> [    9.820107] mwifiex_sdio mmc2:0001:1: Direct firmware
>                load for mrvl/sd8797_uapsta.bin failed with error -2
> [    9.820114] __fw_free_buf: fw-mrvl/sd8797_uapsta.bin
>                buf=ed943a00 data=  (null) size=0
> [    9.820120] mwifiex_sdio mmc2:0001:1: Failed to get
>                firmware mrvl/sd8797_uapsta.bin
> 
> anyway I read on the irc logs that someone got it working
> as a module. By now I imagine my kernel is outdated
> ( 3.19.0-next-20150216 ) Maybe I should upgrade or maybe I
> should just wait until 19.1. I need the kernel headers.
> 
> Of interest is as I mentioned on irc was with shutdown -h
> now the led on the power button does not turn off. Also the
> screen doesn't turn off. It just dims. This you can find out
> by makeing your background white with some black objects in
> it for contrast. Also when it is in this state the current
> draw is about 500mA. Normal operation when the system is not
> particularly busy is at around 670mA, so it hardly shuts
> down at all. Holding down the power button in this state
> shuts it down.
> 
> 
>> There may be some people in IRC who have knowledge on how to flash the
>> chip -- but I don't know that too well personally. Perhaps coreboot is
>> also an option? (Or it that loaded by u-boot?)
> 
> Other way around with infinite variations. I believe
> coreboot launches u-boot as a payload on one particular
> samsung system.
> 
>  I know mostly what to do. U-boot (the original, not forked)
> has recently added "snow" to one of its configurations (a
> little bit like "make exysnosdefonfig" ) and it compiles out
> of the box, and somebody on irc mentioned that they had
> installed it and it works like a dream. I launched it in
> memory and it froze the computer. Thats what I call job
> satisfaction. There are reasons for the freeze but it would
> be nice to have something that would act both as a chained
> bootloader and a bootloader. Coreboot might actually be
> better but the problem is "snow". Everything later is okay.
> My only requirement is like everything on this system it has
> to be compiled on this system. No 3 year old binaries.
> The big problem is that if you make a mistake you no longer
> have a computer and have to go to hell and back and spend
> more money than the worth of your computer for additional
> equipment and have to have an addition computer to get it
> working again so I want to sit and think for a long
> time until I venture to try it.
> 
> 
> Bruce
> 
> _______________________________________________
> Linux-exynos mailing list
> Linux-exynos at linux-exynos.org
> http://lists.linux-exynos.org/listinfo/linux-exynos
> 


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