Re: bug in mmc driver

From: Oskar Holmlund <info_at_ohdata.se>
Date: Mon, 08 Nov 2021 10:37:22 UTC
2021-11-01 08:25 skrev Kamal R. Prasad:
> yes it is a problem in mmc/sd controller. I will check if the no of
> times we release bus matches acquiring bus.
> 
> The controller is a micron controller with this output from
> # geom ls disk
> 
> Geom name: flash/spi0
> 
> Providers:
> 
> 1. Name: flash/spi0
> 
>    Mediasize: 67108864 (64M)
> 
>    Sectorsize: 512
> 
>    Stripesize: 262144
> 
>    Stripeoffset: 0
> 
>    Mode: r0w0e0
> 
>    descr: s25fl512s
> 
>    ident: (null)
> 
>    rotationrate: unknown
> 
>    fwsectors: 0
> 
>    fwheads: 0
> 
> 
> 
> Geom name: mmcsd0
> 
> Providers:
> 
> 1. Name: mmcsd0
> 
>    Mediasize: 14763950080 (14G)
> 
>    Sectorsize: 512
> 
>    Stripesize: 512
> 
>    Stripeoffset: 0
> 
>    Mode: r2w2e5
> 
>    descr: MMCHC R1J57L 1.1 SN 81687B5C MFG 11/2017 by 19 0x004e
> 
>    ident: 81687B5C
> 
>    rotationrate: 0
> 
>    fwsectors: 0
> 
>    fwheads: 0
> 
> 
> On Sat, Oct 30, 2021 at 12:04 AM Ian Lepore <ian@freebsd.org> wrote:
>> 
>> On Fri, 2021-10-29 at 10:02 +0530, Kamal R. Prasad wrote:
>> > hello,
>> >
>> > if i run a stress test on a freebsd system booted from a micron mmc
>> > device, and run a script which in a loop opens the same mmc device in
>> > read-only mode, it causes a problem in acquiring the bus and panics
>> > the box. both the stress test and a script to open the mmc device in
>> > read only mode are in user space and so kernel should not have
>> > panic'ed. Pl see stack trace from our freebsd derived os.
>> >
>> > thanks
>> > -kamal
>> > --------------
>> >
>> > panic: mmc: host bridge didn't serialize us.
>> >
>> > [...]
>> >
>> 
>> This indicates a problem in the low-level mmc/sd controller ("host
>> bridge") driver.  You didn't say anything about what hardware is in
>> use; I have no idea what driver to look at.
>> 
>> -- Ian
>> 
>> 

Hi Kamal,

Can you add your bugreport to
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=255289

Please, share your script and maybe some more details about your 
hardware.

-- 
Bästa Hälsningar
Oskar Holmlund
Tel 070-3220292