The commit 
886275ce41a9751117367fb387ed171049eb6148 (param: lock
if_sdio's lbs_helper_name and lbs_fw_name against sysfs changes)
introduced new fields into the if_sdio_card structure. It caused
missalignment of the if_sdio_card.buffer field and failure at driver
load time:
  ~# modprobe libertas_sdio
  [   62.315124] libertas_sdio: Libertas SDIO driver
  [   62.319976] libertas_sdio: Copyright Pierre Ossman
  [   63.020629] DMA misaligned error with device 48
  [   63.025207] mmci-omap-hs mmci-omap-hs.1: unexpected dma status 800
  [   66.005035] libertas: command 0x0003 timed out
  [   66.009826] libertas: Timeout submitting command 0x0003
  [   66.016296] libertas: PREP_CMD: command 0x0003 failed: -110
Adding explicit alignment attribute for the if_sdio_card.buffer field
fixes this problem.
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
 
        const char              *helper;
        const char              *firmware;
 
-       u8                      buffer[65536];
+       u8                      buffer[65536] __attribute__((aligned(4)));
 
        spinlock_t              lock;
        struct if_sdio_packet   *packets;