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i.mx6solo fat32 USB disk hotplugging

Question asked by Mamoru Kanou on Nov 22, 2014
Latest reply on Feb 27, 2015 by Kaloyan Tenchov

Hi, all

 

Would you please help us seek technical support from Freescale regarding FAT32 USB disk hotplugging?

 

We are using Freescale BSP (version L3.0.35_4.1.0) on imx6.solo processor. When we do FAT32 USB disk hotplugging test we met the following problem:

         Repeatedly plug and unplug a FAT32 USB disk.

During the time period when the usb disk is mounted, A user program continuously reads the USB disk structure.

After thousands of times of test, sometimes the user program thread is put into dormant state and the sleep reason is “sleep_on_buffer”. (we believe this means the kernel code fs/buffer.c, sleep_on_buffer() function). When this happens the USB disk can still be accessed from other user program.

Could you please give us hint on what might be the possible reason and how to avoid it?

For your info the relevant kernel config is like this:

CONFIG_FS_MBCACHE=y

# CONFIG_REISERFS_FS is not set

# CONFIG_JFS_FS is not set

# CONFIG_XFS_FS is not set

# CONFIG_GFS2_FS is not set

# CONFIG_BTRFS_FS is not set

# CONFIG_NILFS2_FS is not set

# CONFIG_FS_POSIX_ACL is not set

CONFIG_FILE_LOCKING=y

CONFIG_FSNOTIFY=y

CONFIG_DNOTIFY=y

CONFIG_INOTIFY_USER=y

# CONFIG_FANOTIFY is not set

# CONFIG_QUOTA is not set

# CONFIG_QUOTACTL is not set

CONFIG_AUTOFS4_FS=y

# CONFIG_FUSE_FS is not set

 

# CONFIG_FSCACHE is not set

CONFIG_FAT_FS=y

CONFIG_MSDOS_FS=y

CONFIG_VFAT_FS=y

CONFIG_FAT_DEFAULT_CODEPAGE=437

CONFIG_FAT_DEFAULT_IOCHARSET="iso8859-1"

# CONFIG_NTFS_FS is not set

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