Hi Linus, Am Mittwoch, 4. September 2024, 00:53:42 CEST schrieb Linus Walleij: > On Fri, Apr 19, 2024 at 10:35 AM Thomas Zimmermann <tzimmermann@xxxxxxx> wrote: > > > Add support for damage handling and deferred I/O to fbdev-dma. This > > enables fbdev-dma to support all DMA-memory-based DRM drivers, even > > such with a dirty callback in their framebuffers. > > > > The patch adds the code for deferred I/O and also sets a dedicated > > helper for struct fb_ops.fb_mmap that support coherent mappings. > > > > v3: > > - init fb_ops with FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS() (Javier) > > > > Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> > > Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx> > > For some reason this makes the Versatile Express crash in QEMU > (I can retest on real hardware if necessary): This commit also breaks i.MX6 on actual hardware, see [1]. [1] https://lore.kernel.org/all/23636953.6Emhk5qWAg@steina-w/ > 8<--- cut here --- > Unable to handle kernel paging request at virtual address 18095000 when write > [18095000] *pgd=00000000 > Internal error: Oops: 805 [#1] SMP ARM > CPU: 0 PID: 75 Comm: S08_ledflash Not tainted 6.9.0-rc6+ #44 > Hardware name: ARM-Versatile Express > PC is at mmioset+0x34/0xac > LR is at 0x0 > pc : [<809c2a54>] lr : [<00000000>] psr: 20000013 > sp : f8dddc38 ip : 18095000 fp : 00000000 > r10: 81109a18 r9 : 81238b04 r8 : 00000000 > r7 : 00440dc0 r6 : ed4f32a0 r5 : ed4f32a0 r4 : 00000001 > r3 : 00000000 r2 : 00000fc0 r1 : 00000000 r0 : 18095000 > Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none > Control: 10c5387d Table: 81d6406a DAC: 00000051 > Register r0 information: non-paged memory > Register r1 information: NULL pointer > Register r2 information: non-paged memory > Register r3 information: NULL pointer > Register r4 information: non-paged memory > Register r5 information: non-slab/vmalloc memory > Register r6 information: non-slab/vmalloc memory > Register r7 information: non-paged memory > Register r8 information: NULL pointer > Register r9 information: non-slab/vmalloc memory > Register r10 information: non-slab/vmalloc memory > Register r11 information: NULL pointer > Register r12 information: non-paged memory > Process S08_ledflash (pid: 75, stack limit = 0x(ptrval)) > Stack: (0xf8dddc38 to 0xf8dde000) > dc20: 00000801 802af888 > dc40: 80a0fb80 00440dc0 00000801 811fad80 00000000 f8dddd28 ed4f32a0 811fa680 > dc60: 00000000 802b0c30 ee1d2140 ee1d215c 95ff4385 00000001 00000001 00000001 > dc80: 00000000 00000000 ffffffff 8196a70b 000000b0 00000064 0000006c 00000000 > dca0: 00000001 00000002 00000001 811fa798 00000801 811fa940 80a0fb80 00000cc0 > dcc0: 00000001 00000001 00000000 f8dddd28 811fa93c 811fa680 00000002 802b0c30 > dce0: ee1d2140 00440dc0 00000000 00000000 00000001 00000000 811fad80 00440dc0 > dd00: 00000001 00000000 00000000 83201100 00440dc0 00000000 00000000 802afa18 > dd20: 00000bdc 00000bd8 811fad80 00000000 811fad80 00000000 00000000 00000000 > dd40: adf00ec5 816d5fa8 816d5fa8 821c3c00 00000000 7ebc2000 7ebe3000 00000000 > dd60: f8ddde44 8028cfa0 816d5fa8 8288df50 8169cf00 821c3c00 7ebc2000 7ebe3000 > dd80: f8ddde44 8028e1e8 00000001 80bbe932 f8ddde44 f8dddde8 f8ddde44 8288df50 > dda0: 83201100 809cf474 f8ddde44 8169cf00 00000020 8169cf94 821c3c94 7ebe3000 > ddc0: 7ebe2fff fffffff4 00000000 816d5fa8 821c3c00 8169cf00 81d65fa8 809cdbb0 > dde0: 8288df50 81ffa910 7ebe3000 82890b00 00000000 00000000 00000000 00000000 > de00: 00000000 00000000 adf00ec5 00000000 00000000 8169cf00 8288df50 83201100 > de20: 821c3c00 81ffa910 f8ddde44 8011f6e4 00000000 00000000 821c3c7c 8169cf7c > de40: 83200880 821c3c40 7ebc2000 7ebe2fff 82890b0c 76ea4000 ffffffff 00000000 > de60: 00000000 0f000a01 f8ddde68 f8ddde68 adf00ec5 00000000 00000000 00000000 > de80: 00000000 01200000 83201100 00000000 00000000 8011e2ac 00000000 83200d7c > dea0: 83201020 83200e70 83200e80 00000000 f8dddf30 83200880 00000000 00000000 > dec0: 00000000 00000000 00000000 82182f38 adf00ec5 00000000 01200000 f8dddf30 > dee0: 00000000 00000000 00000000 00000078 000cb21c 8011fe24 00000020 00000000 > df00: 828a5d80 80a10140 adf00ec5 01200011 00000000 00000000 00000000 f8dddf30 > df20: 00000000 00000078 000cb21c 801203d4 01200000 00000000 00000000 76f46468 > df40: 00000000 00000000 00000011 00000000 00000000 00000000 00000000 00000000 > df60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > df80: 00000003 adf00ec5 76f46468 00000000 76f468c0 00000078 80100290 83201100 > dfa0: 000cb21c 80100060 76f46468 00000000 01200011 00000000 00000000 00000000 > dfc0: 76f46468 00000000 76f468c0 00000078 00000000 76e81000 76f46400 000cb21c > dfe0: 00000078 7ebe2938 76e0854d 76dae7e6 20000030 01200011 00000000 00000000 > Call trace: > mmioset from prep_new_page+0x160/0x194 > prep_new_page from get_page_from_freelist+0x10f4/0x110c > get_page_from_freelist from __alloc_pages+0x15c/0x280 > __alloc_pages from __pte_alloc+0x28/0x1bc > __pte_alloc from copy_page_range+0xc10/0xd28 > copy_page_range from copy_mm+0x5cc/0x850 > copy_mm from copy_process+0x508/0xd8c > copy_process from kernel_clone+0x94/0x338 > kernel_clone from sys_clone+0x94/0xb0 > sys_clone from ret_fast_syscall+0x0/0x1c > Exception stack(0xf8dddfa8 to 0xf8dddff0) > dfa0: 76f46468 00000000 01200011 00000000 00000000 00000000 > dfc0: 76f46468 00000000 76f468c0 00000078 00000000 76e81000 76f46400 000cb21c > dfe0: 00000078 7ebe2938 76e0854d 76dae7e6 > Code: e92d4100 e1a08001 e1a0e003 e2522040 (a8ac410a) > ---[ end trace 0000000000000000 ]--- > > I bisected down to this commit and reverting the commit solves the issue. > > What is special about the Versatile Express graphics is that it uses a special > dedicated video RAM, looks like this in the device tree > > > reserved-memory { > #address-cells = <1>; > #size-cells = <1>; > ranges; > > /* Chipselect 3 is physically at 0x4c000000 */ > vram: vram@4c000000 { > /* 8 MB of designated video RAM */ > compatible = "shared-dma-pool"; > reg = <0x4c000000 0x00800000>; Can you please check in which memory zone this VRAM is located. In my case it's important CMA is located in Normal zone to trigger this problem. Best regards, Alexander > no-map; > }; > }; > (...) > clcd@1f000 { > compatible = "arm,pl111", "arm,primecell"; > (...) > memory-region = <&vram>; > > This gets picked up in the driver > drivers/gpu/drm/pl111/pl111_drv.c > like this: > > ret = of_reserved_mem_device_init(dev); > if (!ret) { > dev_info(dev, "using device-specific reserved memory\n"); > priv->use_device_memory = true; > } > > Yours, > Linus Walleij > -- TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany Amtsgericht München, HRB 105018 Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider http://www.tq-group.com/
