On Fri, Dec 09, 2011 at 09:25:43PM -0500, Jerome Glisse wrote:
Hi Konrad i stumble on this after a long period of test :
Dec 9 12:00:37 homer kernel: ------------[ cut here ]------------ Dec 9 12:00:37 homer kernel: WARNING: at lib/dma-debug.c:894 check_unmap+0x262/0x7e0() Dec 9 12:00:37 homer kernel: Hardware name: GA-A75M-UD2H Dec 9 12:00:37 homer kernel: radeon 0000:01:00.0: DMA-API: device driver frees DMA memory with different CPU address [device address=0x00000002093f3000] [size=4096 bytes] [cpu alloc address=0x0000000213bf2000] [cpu free address=0x00000002093f3000] Dec 9 12:00:37 homer kernel: Modules linked in: radeon ttm drm_kms_helper drm ip6t_REJECT ipt_REJECT nf_conntrack_ipv6 nf_conntrack_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 xt_state nf_conntrack ip6table_filter iptable_filter ip6_tables ip_tables dm_mirror dm_region_hash dm_log dm_mod snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device r8169 snd_pcm microcode serio_raw xhci_hcd mii hwmon i2c_piix4 i2c_algo_bit snd_timer snd soundcore snd_page_alloc ipv6 ext4 mbcache jbd2 ata_generic pata_atiixp [last unloaded: drm] Dec 9 12:00:37 homer kernel: Pid: 1158, comm: Heaven_x64 Not tainted 3.2.0-rc4+ #72 Dec 9 12:00:37 homer kernel: Call Trace: Dec 9 12:00:37 homer kernel: [<ffffffff81043d0f>] warn_slowpath_common+0x7f/0xc0 Dec 9 12:00:37 homer kernel: [<ffffffff81043e06>] warn_slowpath_fmt+0x46/0x50 Dec 9 12:00:37 homer kernel: [<ffffffff81229382>] check_unmap+0x262/0x7e0 Dec 9 12:00:37 homer kernel: [<ffffffff81113977>] ?vm_unmap_aliases+0x77/0x1d0 Dec 9 12:00:37 homer kernel: [<ffffffff8122996d>] debug_dma_free_coherent+0x6d/0x80 Dec 9 12:00:37 homer kernel: [<ffffffff8104bb60>] ?__request_resource+0x60/0x60 Dec 9 12:00:37 homer kernel: [<ffffffffa03e7597>] __ttm_dma_free_page+0x67/0xd0 [ttm] Dec 9 12:00:37 homer kernel: [<ffffffffa03e7f45>] ttm_dma_unpopulate+0x2c5/0x340 [ttm] Dec 9 12:00:37 homer kernel: [<ffffffffa042a81f>] radeon_ttm_tt_unpopulate+0xdf/0xf0 [radeon]
.. snip..
Dec 9 12:00:37 homer kernel: Mapped at: Dec 9 12:00:37 homer kernel: [<ffffffff812282eb>] debug_dma_alloc_coherent+0x3b/0x90 Dec 9 12:00:37 homer kernel: [<ffffffffa03e84a0>] ttm_dma_populate+0x340/0xa30 [ttm] Dec 9 12:00:37 homer kernel: [<ffffffffa042ae4f>] radeon_ttm_tt_populate+0x19f/0x280 [radeon] Dec 9 12:00:37 homer kernel: [<ffffffffa03df0ae>] ttm_tt_bind+0x3e/0x70 [ttm] Dec 9 12:00:37 homer kernel: [<ffffffffa03e0fcf>] ttm_bo_handle_move_mem+0x36f/0x3e0 [ttm] Dec 9 12:01:29 homer kernel: DMA-API: debugging out of memory - disabling Dec 9 19:16:54 homer kernel: [drm:radeon_dvi_detect] *ERROR* DVI-I-1: probed a monitor but no|invalid EDID
Nothing else in the log. Quite frankly i dont this how this can happen. Any ideas ?
The only way to do that would be to modify the 'struct dma_page' vaddr and dma variables from what they had in __ttm_dma_alloc_page. But I am not seeing any willfull modifications. We do pass in to dma_free_coherent the _same_ values!
Hm, it might be worth adding in the 'struct dma_page' a 'virt_to_phys' value (which is what the DMA debug API uses to check), and see we get inconsitent values _before_ we call the DMA debug API. This is rather to double check the DMA API debug API. I am going to try something like this (not compile tested at all):
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c index 6678abc..2dd7d6c 100644 --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c @@ -127,6 +127,7 @@ struct dma_page { void *vaddr; struct page *p; dma_addr_t dma; + void *phys; /* Based on virt_to_phys so not really bus addr */ };
/* @@ -330,6 +331,11 @@ static int ttm_set_pages_caching(struct dma_pool *pool, static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page) { dma_addr_t dma = d_page->dma; + + WARN_ON(virt_to_phys(d_page->vaddr) != d_page->virt, + "WTF: saved 0x%lx, but now we get 0x%lx!\n", + d_page->virt, virt_to_phys(d_page->vaddr)); + dma_free_coherent(pool->dev, pool->size, d_page->vaddr, dma);
kfree(d_page); @@ -348,6 +354,7 @@ static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool) pool->gfp_flags); if (d_page->vaddr) d_page->p = virt_to_page(d_page->vaddr); + d_page->virt = virt_to_phys(d_page->vaddr); else { kfree(d_page); d_page = NULL;