[PATCH] spi: spi-fsl-dspi: Free DMA memory with matching function

[PATCH] spi: spi-fsl-dspi: Free DMA memory with matching function

[Krzysztof Kozlowski]

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>
---
 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

Re: [PATCH] spi: spi-fsl-dspi: Free DMA memory with matching function

[Vladimir Oltean]

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

Re: [PATCH] spi: spi-fsl-dspi: Free DMA memory with matching function

[Mark Brown]

On Wed, 10 Jun 2020 17:41:57 +0200, 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

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: spi-fsl-dspi: Free DMA memory with matching function
      commit: 03fe7aaf0c3d40ef7feff2bdc7180c146989586a

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark