• Soren Brinkmann's avatar
    net: macb: DMA-unmap full rx-buffer · 48330e08
    Soren Brinkmann authored
    When allocating RX buffers a fixed size is used, while freeing is based
    on actually received bytes, resulting in the following kernel warning
    when CONFIG_DMA_API_DEBUG is enabled:
     WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1051 check_unmap+0x258/0x894()
     macb e000b000.ethernet: DMA-API: device driver frees DMA memory with different size [device address=0x000000002d170040] [map size=1536 bytes] [unmap size=60 bytes]
     Modules linked in:
     CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc3-xilinx-00220-g49f84081ce4f #65
     [<c001516c>] (unwind_backtrace) from [<c0011df8>] (show_stack+0x10/0x14)
     [<c0011df8>] (show_stack) from [<c03c775c>] (dump_stack+0x7c/0xc8)
     [<c03c775c>] (dump_stack) from [<c00245cc>] (warn_slowpath_common+0x60/0x84)
     [<c00245cc>] (warn_slowpath_common) from [<c0024670>] (warn_slowpath_fmt+0x2c/0x3c)
     [<c0024670>] (warn_slowpath_fmt) from [<c0227d44>] (check_unmap+0x258/0x894)
     [<c0227d44>] (check_unmap) from [<c0228588>] (debug_dma_unmap_page+0x64/0x70)
     [<c0228588>] (debug_dma_unmap_page) from [<c02ab78c>] (gem_rx+0x118/0x170)
     [<c02ab78c>] (gem_rx) from [<c02ac4d4>] (macb_poll+0x24/0x94)
     [<c02ac4d4>] (macb_poll) from [<c031222c>] (net_rx_action+0x6c/0x188)
     [<c031222c>] (net_rx_action) from [<c0028a28>] (__do_softirq+0x108/0x280)
     [<c0028a28>] (__do_softirq) from [<c0028e8c>] (irq_exit+0x84/0xf8)
     [<c0028e8c>] (irq_exit) from [<c000f360>] (handle_IRQ+0x68/0x8c)
     [<c000f360>] (handle_IRQ) from [<c0008528>] (gic_handle_irq+0x3c/0x60)
     [<c0008528>] (gic_handle_irq) from [<c0012904>] (__irq_svc+0x44/0x78)
     Exception stack(0xc056df20 to 0xc056df68)
     df20: 00000001 c0577430 00000000 c0577430 04ce8e0d 00000002 edfce238 00000000
     df40: 04e20f78 00000002 c05981f4 00000000 00000008 c056df68 c0064008 c02d7658
     df60: 20000013 ffffffff
     [<c0012904>] (__irq_svc) from [<c02d7658>] (cpuidle_enter_state+0x54/0xf8)
     [<c02d7658>] (cpuidle_enter_state) from [<c02d77dc>] (cpuidle_idle_call+0xe0/0x138)
     [<c02d77dc>] (cpuidle_idle_call) from [<c000f660>] (arch_cpu_idle+0x8/0x3c)
     [<c000f660>] (arch_cpu_idle) from [<c006bec4>] (cpu_startup_entry+0xbc/0x124)
     [<c006bec4>] (cpu_startup_entry) from [<c053daec>] (start_kernel+0x350/0x3b0)
     ---[ end trace d5fdc38641bd3a11 ]---
     Mapped at:
      [<c0227184>] debug_dma_map_page+0x48/0x11c
      [<c02ab32c>] gem_rx_refill+0x154/0x1f8
      [<c02ac7b4>] macb_open+0x270/0x3e0
      [<c03152e0>] __dev_open+0x7c/0xfc
      [<c031554c>] __dev_change_flags+0x8c/0x140
    
    Fixing this by passing the same size which is passed during mapping the
    memory to the unmap function as well.
    Signed-off-by: default avatarSoren Brinkmann <soren.brinkmann@xilinx.com>
    Reviewed-by: default avatarBen Hutchings <ben@decadent.org.uk>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    48330e08
macb.c 50.4 KB