Re: [v2] drm/komeda: fixing of DMA mapping sg segment warning
From: james qian wang (Arm Technology China)
Date: Mon May 20 2019 - 02:04:29 EST
On Thu, Apr 11, 2019 at 08:37:13AM +0000, Lowry Li (Arm Technology China) wrote:
> Fixing the DMA mapping sg segment warning, which shows "DMA-API: mapping
> sg segment longer than device claims to support [len=921600] [max=65536]".
> Fixed by setting the max segment size at Komeda driver.
>
> This patch depends on:
> - https://patchwork.freedesktop.org/series/54448/
> - https://patchwork.freedesktop.org/series/54449/
> - https://patchwork.freedesktop.org/series/54450/
> - https://patchwork.freedesktop.org/series/58976/
>
> Changes since v1:
> - Adds member description
> - Adds patch denpendency in the comment
>
> Signed-off-by: Lowry Li (Arm Technology China) <lowry.li@xxxxxxx>
> ---
> drivers/gpu/drm/arm/display/komeda/komeda_dev.c | 4 ++++
> drivers/gpu/drm/arm/display/komeda/komeda_dev.h | 2 ++
> 2 files changed, 6 insertions(+)
>
> --
> 1.9.1
>
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> index 7f25e6a..b4902ae 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> @@ -8,6 +8,7 @@
> #include <linux/of_device.h>
> #include <linux/of_graph.h>
> #include <linux/platform_device.h>
> +#include <linux/dma-iommu.h>
> #ifdef CONFIG_DEBUG_FS
> #include <linux/debugfs.h>
> #include <linux/seq_file.h>
> @@ -245,6 +246,9 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
> goto err_cleanup;
> }
>
> + dev->dma_parms = &mdev->dma_parms;
> + dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
> +
> err = sysfs_create_group(&dev->kobj, &komeda_sysfs_attr_group);
> if (err) {
> DRM_ERROR("create sysfs group failed.\n");
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> index 29e03c4..83ace71 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> @@ -149,6 +149,8 @@ struct komeda_dev {
> struct device *dev;
> /** @reg_base: the base address of komeda io space */
> u32 __iomem *reg_base;
> + /** @dma_parms: the dma parameters of komeda */
> + struct device_dma_parameters dma_parms;
>
> /** @chip: the basic chip information */
> struct komeda_chip_info chip;
Looks good to me.
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@xxxxxxx>