On 6/10/20 6:42 PM, Krzysztof Kozlowski wrote:

Driver allocates DMA memory with dma_alloc_coherent() but frees it with dma_unmap_single().

This causes DMA warning during system shutdown (with DMA debugging) on Toradex Colibri VF50 module:

 WARNING: CPU: 0 PID: 1 at ../kernel/dma/debug.c:1036 check_unmap+0x3fc/0xb04
 DMA-API: fsl-edma 40098000.dma-controller: device driver frees DMA memory with wrong function
   [device address=0x0000000087040000] [size=8 bytes] [mapped as coherent] [unmapped as single]
 Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
   (unwind_backtrace) from [<8010bb34>] (show_stack+0x10/0x14)
   (show_stack) from [<8011ced8>] (__warn+0xf0/0x108)
   (__warn) from [<8011cf64>] (warn_slowpath_fmt+0x74/0xb8)
   (warn_slowpath_fmt) from [<8017d170>] (check_unmap+0x3fc/0xb04)
   (check_unmap) from [<8017d900>] (debug_dma_unmap_page+0x88/0x90)
   (debug_dma_unmap_page) from [<80601d68>] (dspi_release_dma+0x88/0x110)
   (dspi_release_dma) from [<80601e4c>] (dspi_shutdown+0x5c/0x80)
   (dspi_shutdown) from [<805845f8>] (device_shutdown+0x17c/0x220)
   (device_shutdown) from [<80143ef8>] (kernel_restart+0xc/0x50)
   (kernel_restart) from [<801441cc>] (__do_sys_reboot+0x18c/0x210)
   (__do_sys_reboot) from [<80100060>] (ret_fast_syscall+0x0/0x28)
 DMA-API: Mapped at:
  dma_alloc_attrs+0xa4/0x130
  dspi_probe+0x568/0x7b4
  platform_drv_probe+0x6c/0xa4
  really_probe+0x208/0x348
  driver_probe_device+0x5c/0xb4

Fixes: 90ba37033cb9 ("spi: spi-fsl-dspi: Add DMA support for Vybrid") Cc: stable@vger.kernel.org Signed-off-by: Krzysztof Kozlowski krzk@kernel.org

---

Sounds reasonable. I always wondered why err_slave_config and err_rx_dma_buf call something different than dspi_release_dma, but I didn't see any problem so I didn't investigate it further.

Acked-by: Vladimir Oltean vladimir.oltean@nxp.com

drivers/spi/spi-fsl-dspi.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index a35faced0456..58190c94561f 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -588,14 +588,14 @@ static void dspi_release_dma(struct fsl_dspi *dspi) return;

     if (dma->chan_tx) {

•           dma_unmap_single(dma->chan_tx->device->dev, dma->tx_dma_phys,
  

•                            dma_bufsize, DMA_TO_DEVICE);
  

•           dma_free_coherent(dma->chan_tx->device->dev, dma_bufsize,
  

•                             dma->tx_dma_buf, dma->tx_dma_phys);
             dma_release_channel(dma->chan_tx);
     }
  
     if (dma->chan_rx) {
  

•           dma_unmap_single(dma->chan_rx->device->dev, dma->rx_dma_phys,
  

•                            dma_bufsize, DMA_FROM_DEVICE);
  

•           dma_free_coherent(dma->chan_rx->device->dev, dma_bufsize,
  

•                             dma->rx_dma_buf, dma->rx_dma_phys);
             dma_release_channel(dma->chan_rx);
     }
  

  }

-- 2.7.4

Thanks! -Vladimir