Ping. On Mon, Feb 25, 2019 at 10:54:23AM +0000, Russell King - ARM Linux admin wrote: > On Mon, Feb 25, 2019 at 10:51:30AM +0000, Russell King wrote: > > During boot, I get this kernel warning: > > > > WARNING: CPU: 0 PID: 19001 at kernel/dma/debug.c:1301 debug_dma_map_sg+0x284/0x3dc > > etnaviv etnaviv: DMA-API: mapping sg segment longer than device claims to support [len=3145728] [max=65536] > > Modules linked in: ip6t_REJECT nf_reject_ipv6 ip6t_rpfilter xt_tcpudp ipt_REJECT nf_reject_ipv4 xt_conntrack ip_set nfnetlink ebtable_broute ebtable_nat ip6table_raw ip6table_nat nf_nat_ipv6 ip6table_mangle iptable_raw iptable_nat nf_nat_ipv4 nf_nat nf_conntrack nf_defrag_ipv4 nf_defrag_ipv6 libcrc32c iptable_mangle ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter caam_jr error snd_soc_imx_spdif imx_thermal snd_soc_imx_audmux nvmem_imx_ocotp snd_soc_sgtl5000 > > caam imx_sdma virt_dma coda rc_cec v4l2_mem2mem snd_soc_fsl_ssi snd_soc_fsl_spdif imx_vdoa imx_pcm_dma videobuf2_dma_contig etnaviv dw_hdmi_cec gpu_sched dw_hdmi_ahb_audio imx6q_cpufreq nfsd sch_fq_codel ip_tables x_tables > > CPU: 0 PID: 19001 Comm: Xorg Not tainted 4.20.0+ #307 > > Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) > > [<c0019658>] (unwind_backtrace) from [<c001489c>] (show_stack+0x10/0x14) > > [<c001489c>] (show_stack) from [<c07fb420>] (dump_stack+0x9c/0xd4) > > [<c07fb420>] (dump_stack) from [<c00312dc>] (__warn+0xf8/0x124) > > [<c00312dc>] (__warn) from [<c00313d0>] (warn_slowpath_fmt+0x38/0x48) > > [<c00313d0>] (warn_slowpath_fmt) from [<c00b14e8>] (debug_dma_map_sg+0x284/0x3dc) > > [<c00b14e8>] (debug_dma_map_sg) from [<c046eb40>] (drm_gem_map_dma_buf+0xc4/0x13c) > > [<c046eb40>] (drm_gem_map_dma_buf) from [<c04c3314>] (dma_buf_map_attachment+0x38/0x5c) > > [<c04c3314>] (dma_buf_map_attachment) from [<c046e728>] (drm_gem_prime_import_dev+0x74/0x104) > > [<c046e728>] (drm_gem_prime_import_dev) from [<c046e5bc>] (drm_gem_prime_fd_to_handle+0x84/0x17c) > > [<c046e5bc>] (drm_gem_prime_fd_to_handle) from [<c046edd0>] (drm_prime_fd_to_handle_ioctl+0x38/0x4c) > > [<c046edd0>] (drm_prime_fd_to_handle_ioctl) from [<c0460efc>] (drm_ioctl_kernel+0x90/0xc8) > > [<c0460efc>] (drm_ioctl_kernel) from [<c0461114>] (drm_ioctl+0x1e0/0x3b0) > > [<c0461114>] (drm_ioctl) from [<c01cae20>] (do_vfs_ioctl+0x90/0xa48) > > [<c01cae20>] (do_vfs_ioctl) from [<c01cb80c>] (ksys_ioctl+0x34/0x60) > > [<c01cb80c>] (ksys_ioctl) from [<c0009000>] (ret_fast_syscall+0x0/0x28) > > Exception stack(0xd81a9fa8 to 0xd81a9ff0) > > 9fa0: b6c69c88 bec613f8 00000009 c00c642e bec613f8 b86c4600 > > 9fc0: b6c69c88 bec613f8 c00c642e 00000036 012762e0 01276348 00000300 012d91f8 > > 9fe0: b6989f18 bec613dc b697185c b667be5c > > irq event stamp: 47905 > > hardirqs last enabled at (47913): [<c0098824>] console_unlock+0x46c/0x680 > > hardirqs last disabled at (47922): [<c0098470>] console_unlock+0xb8/0x680 > > softirqs last enabled at (47754): [<c000a484>] __do_softirq+0x344/0x540 > > softirqs last disabled at (47701): [<c0038700>] irq_exit+0x124/0x144 > > ---[ end trace af477747acbcc642 ]--- > > > > The reason is the contiguous buffer exceeds the default maximum segment > > size of 64K as specified by dma_get_max_seg_size() in > > linux/dma-mapping.h. Fix this by providing our own segment size, which > > is set to 2GiB to cover the window found in MMUv1 GPUs. > > > > Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> > > Fixes: 78c47830a5cb ("dma-debug: check scatterlist segments") > > not really that there's a problem with that commit, but it is where the > warning was introduced. > > > --- > > Patch against v4.20. > > > > drivers/gpu/drm/etnaviv/etnaviv_drv.c | 4 ++++ > > drivers/gpu/drm/etnaviv/etnaviv_drv.h | 1 + > > 2 files changed, 5 insertions(+) > > > > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c > > index 4713885012ab..e414f284f424 100644 > > --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.c > > +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.c > > @@ -527,6 +527,9 @@ static int etnaviv_bind(struct device *dev) > > } > > drm->dev_private = priv; > > > > + dev->dma_parms = &priv->dma_parms; > > + dma_set_max_seg_size(dev, SZ_2G); > > + > > mutex_init(&priv->gem_lock); > > INIT_LIST_HEAD(&priv->gem_list); > > priv->num_gpus = 0; > > @@ -564,6 +567,7 @@ static void etnaviv_unbind(struct device *dev) > > > > component_unbind_all(dev, drm); > > > > + dev->dma_parms = NULL; > > drm->dev_private = NULL; > > kfree(priv); > > > > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.h b/drivers/gpu/drm/etnaviv/etnaviv_drv.h > > index 8d02d1b7dcf5..b2930d1fe97c 100644 > > --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.h > > +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.h > > @@ -43,6 +43,7 @@ struct etnaviv_file_private { > > > > struct etnaviv_drm_private { > > int num_gpus; > > + struct device_dma_parameters dma_parms; > > struct etnaviv_gpu *gpu[ETNA_MAX_PIPES]; > > > > /* list of GEM objects: */ > > -- > > 2.7.4 > > > > > > -- > RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ > FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up > According to speedtest.net: 11.9Mbps down 500kbps up -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel