Problem solved. The NULL oops is due to the mtd->dev.class->p is NULL, which makes the spin_lock in "get_device_parent" function uses a false spin_lock_t struct. the line is "spin_lock(&dev->class->p->class_dirs.list_lock);" That is mainly because in function add_mtd_device function uses the static struct mtd_class to fill into mtd->dev.class. The static struct is not initialized because I drop the driver in our custom dirctory, which is in /arch/powerpc/platforms/..., not in the /drivers/mtd/nand directory, after I put the file there and modifies the Makefile, everything works fine.
2010/3/2 Peter Pan <pppeterpp...@gmail.com>: > > We use Address A20 and A21 connect to ALE and CLE, the data bus is > connected through a buffer. > The RE is OE AND with CS. the WE is PBS0 AND with CS. CE pin is > connect to ground. It works > fine in VxWorks. And also in our previous Linux version 2.6.22. > > Now, I get a odd problem. My GPCM Nand flash driver is mostly copied > from fsl_upm.c. In the fun_probe > function, I have printed out the of_device pointer status as follows: > ofdev= 0xcf851ca0 > ofdev->dev= 0xcf851cb0 > ofdev->dev.class= 0xcf851d50 > > Then I set the &ofdev->dev to mtd.dev.parent using > fun->mtd.dev.parent = &ofdev->dev; > > Then I print out the values: > fun->mtd.dev.parent= 0xcf851cb0 > fun->mtd.dev.parent->class= 0x0 > > The parent pointer is identical, but the class member is NULL, which > makes the access of NULL pointer oops > later. > > I'm wondering why this could happen. The pointer points at the same > address, shouldn't all the members be the > same? > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
