Re: [PATCH 4.19 04/87] drm/msm: Set dma maximum segment size for mdss

[Greg Kroah-Hartman]

On Wed, Mar 04, 2020 at 04:13:16PM +0100, Pavel Machek wrote:
> Hi!
> 
> > Turning on CONFIG_DMA_API_DEBUG_SG results in the following error:
> > 
> > [   12.078665] msm ae00000.mdss: DMA-API: mapping sg segment longer than device claims to support [len=3526656] [max=65536]
> > [   12.089870] WARNING: CPU: 6 PID: 334 at
> > /mnt/host/source/src/third_party/kernel/v4.19/kernel/dma/debug.c:1301
> > debug_dma_map_sg+0x1dc/0x318
> 
> This one leaks resources in the (very improbable) case of error; it
> needs to goto cleanup instead of simply returning.
> 
> > +++ b/drivers/gpu/drm/msm/msm_drv.c
> > @@ -492,6 +492,14 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
> >  	if (ret)
> >  		goto err_msm_uninit;
> >  
> > +	if (!dev->dma_parms) {
> > +		dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
> > +					      GFP_KERNEL);
> > +		if (!dev->dma_parms)
> > +			return -ENOMEM;
> > +	}
> > +	dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
> > +
> >  	msm_gem_shrinker_init(ddev);
> >  

Can you submit a patch to fix it?

thanks,

greg k-h