net: ti: netcp: restore get/set_pad_info() functionality

The commit 899077791403 ("netcp: try to reduce type confusion in
descriptors") introduces a regression in Kernel 4.5-rc1 and it breaks
get/set_pad_info() functionality.

The TI NETCP driver uses pad0 and pad1 fields of knav_dma_desc to
store DMA/MEM buffer pointer and buffer size respectively. And in both
cases for Keystone 2 the pointer type size is 32 bit regardless of
LAPE enabled or not, because CONFIG_ARCH_DMA_ADDR_T_64BIT originally
is not expected to be defined.

Unfortunately, above commit changed buffer's pointers save/restore
code (get/set_pad_info()) and added intermediate conversation to u64
which works incorrectly on 32bit Keystone 2 and causes TI NETCP driver
crash in RX/TX path due to "Unable to handle kernel NULL pointer"
exception. This issue was reported and discussed in [1].

Hence, fix it by partially reverting above commit and restoring
get/set_pad_info() functionality as it was before.

[1] https://www.mail-archive.com/[email protected]/msg95361.html
Cc: Wingman Kwok <[email protected]>
Cc: Mugunthan V N <[email protected]>
CC: David Laight <[email protected]>
CC: Arnd Bergmann <[email protected]>
Reported-by: Franklin S Cooper Jr <[email protected]>
Signed-off-by: Grygorii Strashko <[email protected]>
Signed-off-by: Murali Karicheri <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions