On Thu, Sep 15, 2005 at 05:17:29PM -0400, Bagalkote, Sreenivas wrote: > In our MegaRAID driver, one of the IOCTLs is defined as > #define MEGASAS_IOC_GET_AEN _IOW('M', 2, struct megasas_aen) > > This clashes with some other value in "built_in" ioctl table on x86_64 > kernels. > How do I really avoid such problems in the future. Even if I search the > length > of the built_in table and pick a unique value, is it guaranteed to be unique > in > the future releases? The Documentation/ioctl-number.txt isn't of much help > either. > It lists multiple conflicts. Moreover, not all of them are listed there. > > On a broader note, if the struct ioctl_trans inside ioctl32_hash_table could > use the combination of cmd + major number instead of just cmd to determine > the > uniqueness, these conflicts could be avoided, right? I mean understand the > reasons > for system-wide unique ioctl numbers. But right now, only those platforms > that > need conversion are technically impeded for violating that guideline. Cou can't avoid the clashes in the hash. That's why we got rid of user-registerable ioctl translations completely and only allow ->compat_ioctl anymore. - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html