Doubt on mmc erase command
Hello,
I'm trying to send ERASE Command to the emmc by deleting a file on one of the emmc partitions and then doing a sync, But I'm noticing that even this will not issue the erase command to emmc.
I did trace the code on, from where this erase command is issued, but my trace ended at an ioctl call "do_vfs_ioctl()" more specific "SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)" system call definition does a call to do_vfs_ioctl.
Please help me understand how to initiate this from userspace.
Hi Sheetal,
Try enabling mmc trace events to check what is the cmd you are getting to confirm erase going through.
You shoud get cmd 35/36/38 if erase is going through in case of emmc.
-Ritesh
Quoted 16 lines · Sheetal
Hello,
I'm trying to send ERASE Command to the emmc by deleting a file on one of the emmc partitions and then doing a sync, But I'm noticing that even this will not issue the erase command to emmc.
I did trace the code on, from where this erase command is issued, but my trace ended at an ioctl call "
do_vfs_ioctl()" more specific "SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)" system call definition does a call todo_vfs_ioctl.Please help me understand how to initiate this from userspace. --
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello Ritesh Harjani,
Thanks for the info Ritesh, I'll try out your pointer to mmc trace events next time i run into eMMC issue
In the current case, I found out that in case of file deletion, only the file's metadata(such as entry in inode table, inode_bitmap and other filesystem parameters) is freed and it won't invoke the ERASE command seq explicitly(atleast in case of EXT4 it doesn't send ERASE CMD). I think only in case of formatting(mkfs) of the partition or the whole eMMC, ERASE command is issued.
Thanks
Sheetal
Quoted 30 lines · Ritesh Harjani
Hi Sheetal,
Try enabling mmc trace events to check what is the cmd you are getting to confirm erase going through.
You shoud get cmd 35/36/38 if erase is going through in case of emmc.-Ritesh
Quoted 16 lines · Sheetal
Hello,
I'm trying to send ERASE Command to the emmc by deleting a file on one of the emmc partitions and then doing a sync, But I'm noticing that even this will not issue the erase command to emmc.
I did trace the code on, from where this erase command is issued, but my trace ended at an ioctl call "
do_vfs_ioctl()" more specific "SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)" system call definition does a call todo_vfs_ioctl.Please help me understand how to initiate this from userspace. --
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html