Hi,

Follow up to the original message: I have been trying to bisect the problem,
but haven't determined a definitely "good" kernel yet. The problem certainly
manifests itself on 2.6.36.3 when the config is straight from Arch Linux's
kernel26-headers 2.6.36.3-1 package. If I disable staging drivers (via
CONFIG_STAGING_EXCLUDE_BUILD=y), the problem goes away. Very
annoying to notice that after half a dozen kernel compiles.

Anyway, I have two versions of the 2.6.36.3 kernel+modules, one with
staging drivers (bad) and one without (good). If I take the vmlinuz and
System.map files from the good version and put them together with
the bad modules, it works. So, something in the main kernel instead of
the modules, I assume, but what could be changing there with the staging
switch to cause such a specific problem? In the config all the staging
drivers are set to be modules.

Mikko



----- Original Message ----

From: Mikko Vinni
To: linux-mmc; Chris Ball
Sent: Thu, January 20, 2011 11:04:23 PM
Subject: SD card reads corrupted (JMicron card reader)

Hi,

I have an HP Pavilion dv5 laptop, which has an integrated memory card  reader
(labeled with "SD*MS/Pro*MMC*XD) and appearing with lspci  as:

0a:00.1 System peripheral: JMicron Technology Corp. SD/MMC Host  Controller
0a:00.2 SD Host controller: JMicron Technology Corp. Standard SD  Host 
Controller
0a:00.3 System peripheral: JMicron Technology Corp. MS Host  Controller
0a:00.4 System peripheral: JMicron Technology Corp. xD Host  Controller

I have mainly used a 1 GB SD card from puremedia, but I have  seen the problem
with another card as well. Basically, if I try to read image  files from the 
card 

using the
card reader, the images come out corrupted  (having the card inside a Canon 
Ixus 

camera and reading the images via a USB  cable works).

The logs don't seem to contain anything  suspicious:

[ 1262.957504] sdhci: Secure Digital Host Controller  Interface driver
[ 1262.957511] sdhci: Copyright(c) Pierre Ossman
[  1262.962070] sdhci-pci 0000:0a:00.1: SDHCI controller found [197b:2382] (rev 

0)
[ 1262.962105] sdhci-pci 0000:0a:00.1: PCI INT A -> GSI 18 (level,  low) -> IRQ 

18
[ 1262.962275] sdhci-pci 0000:0a:00.1: setting latency  timer to 64
[ 1262.963721] Registered led device: mmc0::
[ 1262.964075]  mmc0: SDHCI controller on PCI [0000:0a:00.1] using DMA
[ 1262.964110]  sdhci-pci 0000:0a:00.2: SDHCI controller found [197b:2381] (rev 

0)
[  1262.964137] sdhci-pci 0000:0a:00.2: PCI INT A -> GSI 18 (level, low) ->  
IRQ 

18
[ 1262.964158] sdhci-pci 0000:0a:00.2: Refusing to bind to  secondary 
interface.
[ 1262.964170] sdhci-pci 0000:0a:00.2: PCI INT A  disabled
[ 1266.834763] mmc0: new SD card at address 1234
[ 1266.924222]  mmcblk0: mmc0:1234 SD01G 972 MiB 
[ 1266.925586]  mmcblk0: p1
[  2575.746579] mmc0: card 1234 removed
[ 3544.629621] loop: module loaded
[  4747.394461] mmc0: new SD card at address 1234
[ 4747.394793] mmcblk0:  mmc0:1234 SD01G 972 MiB 
[ 4747.396090]  mmcblk0: p1
[ 5075.523021]  mmc0: card 1234 removed

I transferred some text files to the card and  back to see if there's some 
regularity
in the corruption, but it varies.  For example, of 100 files of varying sizes 
(largest 98KB),
at one point  11 files might be corrupted, and after umount/mount maybe 6.

I copied the  memory card file system to a file; loop mounting that file 

system

gives one  stable (but corrupted) view of the files, so I suppose it's not a 
file
system  (vfat) issue, but something with the hardware.

Currently I am using a  custom 2.6.37 kernel (on 64 bit Arch Linux up to date), 

but
I have seen  corrupted images coming from the card reader on several previous
kernels as  well.

Is there something I could test or some specific information I  should 

provide?

quoted hunk

Here is one example of the corruption I am talking  about:
- the source file 49.txt consists of  lines
0049-0001
0049-0002
0049-0003
...
0049-2399
0049-2400
0049-2401

The  file is exactly 24010 bytes long.

After transferring that file to the SD  card and back (via the card reader) and 

taking a diff, the differences  are:

@@ -407,1995 +407,1992 @@
 0049-0407
 0049-0408
  0049-0409
-0049-0410
-0049-0411
-0049-0412

... (all lines in between  removed; each line is 10  bytes)
-0049-2399
-0049-2400
-0049-2401
+0049-00049-0001
+0049-0002
+0049-0003
...  (all lines in between  added)
+0049-0408
+0049-0409
+0049-00049-0001
+0049-0002
+0049-0003
...
+0049-0408
+0049-0409
+0049-00049-0001
+0049-0002
+0049-0003
...
+0049-0407
+0049-0408
+0049-0409
+0049-00049-0001
+0049-0002
+0049-0003
...
+0049-0407
+0049-0408
+0049-0409
+0049-00049-0001
+0049-0002
+0049-0003
...
+0049-0351
+0049-0352
+0049-0353

Also  the corrupted file is exactly 24010 bytes long. In this case there seems
to  be a chunk of 4096 bytes repeating. I'm in no way expert, but if  somebody
thinks it's good to see if the other test files also contain similar  chunks of 

4096
bytes, I can go through them or post them  here.


Any help would be  appreciated.

Mikko