kernel/linux.git/drivers/gpu/drm/drm_modes.c, branch v4.19.265

drm/modes: Prevent division by zero htotal

2019-02-15T07:10:12+00:00

commit a2fcd5c84f7a7825e028381b10182439067aa90d upstream. This patch prevents division by zero htotal. In a follow-up mail Tina writes: > > How did you manage to get here with htotal == 0? This needs backtraces (or if > > this is just about static checkers, a mention of that). > > -Daniel > > In GVT-g, we are trying to enable a virtual display w/o setting timings for a pipe > (a.k.a htotal=0), then we met the following kernel panic: > > [ 32.832048] divide error: 0000 [#1] SMP PTI > [ 32.833614] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.18.0-rc4-sriov+ #33 > [ 32.834438] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.10.1-0-g8891697-dirty-20180511_165818-tinazhang-linux-1 04/01/2014 > [ 32.835901] RIP: 0010:drm_mode_hsync+0x1e/0x40 > [ 32.836004] Code: 31 c0 c3 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 8b 87 d8 00 00 00 85 c0 75 22 8b 4f 68 85 c9 78 1b 69 47 58 e8 03 00 00 99 f9 b9 d3 4d 62 10 05 f4 01 00 00 f7 e1 89 d0 c1 e8 06 f3 c3 66 > [ 32.836004] RSP: 0000:ffffc900000ebb90 EFLAGS: 00010206 > [ 32.836004] RAX: 0000000000000000 RBX: ffff88001c67c8a0 RCX: 0000000000000000 > [ 32.836004] RDX: 0000000000000000 RSI: ffff88001c67c000 RDI: ffff88001c67c8a0 > [ 32.836004] RBP: ffff88001c7d03a0 R08: ffff88001c67c8a0 R09: ffff88001c7d0330 > [ 32.836004] R10: ffffffff822c3a98 R11: 0000000000000001 R12: ffff88001c67c000 > [ 32.836004] R13: ffff88001c7d0370 R14: ffffffff8207eb78 R15: ffff88001c67c800 > [ 32.836004] FS: 0000000000000000(0000) GS:ffff88001da00000(0000) knlGS:0000000000000000 > [ 32.836004] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 32.836004] CR2: 0000000000000000 CR3: 000000000220a000 CR4: 00000000000006f0 > [ 32.836004] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 32.836004] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 32.836004] Call Trace: > [ 32.836004] intel_mode_from_pipe_config+0x72/0x90 > [ 32.836004] intel_modeset_setup_hw_state+0x569/0xf90 > [ 32.836004] intel_modeset_init+0x905/0x1db0 > [ 32.836004] i915_driver_load+0xb8c/0x1120 > [ 32.836004] i915_pci_probe+0x4d/0xb0 > [ 32.836004] local_pci_probe+0x44/0xa0 > [ 32.836004] ? pci_assign_irq+0x27/0x130 > [ 32.836004] pci_device_probe+0x102/0x1c0 > [ 32.836004] driver_probe_device+0x2b8/0x480 > [ 32.836004] __driver_attach+0x109/0x110 > [ 32.836004] ? driver_probe_device+0x480/0x480 > [ 32.836004] bus_for_each_dev+0x67/0xc0 > [ 32.836004] ? klist_add_tail+0x3b/0x70 > [ 32.836004] bus_add_driver+0x1e8/0x260 > [ 32.836004] driver_register+0x5b/0xe0 > [ 32.836004] ? mipi_dsi_bus_init+0x11/0x11 > [ 32.836004] do_one_initcall+0x4d/0x1eb > [ 32.836004] kernel_init_freeable+0x197/0x237 > [ 32.836004] ? rest_init+0xd0/0xd0 > [ 32.836004] kernel_init+0xa/0x110 > [ 32.836004] ret_from_fork+0x35/0x40 > [ 32.836004] Modules linked in: > [ 32.859183] ---[ end trace 525608b0ed0e8665 ]--- > [ 32.859722] RIP: 0010:drm_mode_hsync+0x1e/0x40 > [ 32.860287] Code: 31 c0 c3 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 8b 87 d8 00 00 00 85 c0 75 22 8b 4f 68 85 c9 78 1b 69 47 58 e8 03 00 00 99 f9 b9 d3 4d 62 10 05 f4 01 00 00 f7 e1 89 d0 c1 e8 06 f3 c3 66 > [ 32.862680] RSP: 0000:ffffc900000ebb90 EFLAGS: 00010206 > [ 32.863309] RAX: 0000000000000000 RBX: ffff88001c67c8a0 RCX: 0000000000000000 > [ 32.864182] RDX: 0000000000000000 RSI: ffff88001c67c000 RDI: ffff88001c67c8a0 > [ 32.865206] RBP: ffff88001c7d03a0 R08: ffff88001c67c8a0 R09: ffff88001c7d0330 > [ 32.866359] R10: ffffffff822c3a98 R11: 0000000000000001 R12: ffff88001c67c000 > [ 32.867213] R13: ffff88001c7d0370 R14: ffffffff8207eb78 R15: ffff88001c67c800 > [ 32.868075] FS: 0000000000000000(0000) GS:ffff88001da00000(0000) knlGS:0000000000000000 > [ 32.868983] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 32.869659] CR2: 0000000000000000 CR3: 000000000220a000 CR4: 00000000000006f0 > [ 32.870599] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 32.871598] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 32.872549] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b > > Since drm_mode_hsync() has the logic to check mode->htotal, I just extend it to cover the case htotal==0. Signed-off-by: Tina Zhang Cc: Adam Jackson Cc: Dave Airlie Cc: Daniel Vetter [danvet: Add additional explanations + cc: stable.] Cc: stable@vger.kernel.org Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/1548228539-3061-1-git-send-email-tina.zhang@intel.com Signed-off-by: Greg Kroah-Hartman

drm: drop _mode_ from remaining connector functions

2018-07-13T16:40:27+00:00

Since there's very few callers of these I've decided to do them all in one patch. With this the unecessarily long drm_mode_connector_ prefix is gone from the codebase! The only exception being struct drm_mode_connector_set_property, which is part of the uapi so can't be renamed. Again done with sed+some manual fixups for indent issues. Reviewed-by: Sean Paul Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20180709084016.23750-8-daniel.vetter@ffwll.ch

drm: Add support for extracting sync signal drive edge from videomode

2018-07-10T15:59:05+00:00

The sync in some panels needs to be driven by different edge of the pixel clock compared to data. This is reflected by the DISPLAY_FLAGS_SYNC_(POS|NEG)EDGE in videmode flags. Add similar similar definitions for bus_flags and convert the sync drive edge via drm_bus_flags_from_videomode(). Signed-off-by: Peter Ujfalusi Signed-off-by: Tomi Valkeinen Signed-off-by: Jyri Sarha Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/20180618132242.8673-2-tomi.valkeinen@ti.com

drm: Print bad user modes

2018-06-15T20:31:07+00:00

Print out the modeline when we reject a bad user mode. Avoids having to guess why it was rejected. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20180611193403.16118-2-ville.syrjala@linux.intel.com Reviewed-by: Harry Wentland

drm: Add and handle new aspect ratios in DRM layer

2018-05-11T07:23:55+00:00

HDMI 2.0/CEA-861-F introduces two new aspect ratios: - 64:27 - 256:135 This patch: - Adds new DRM flags for to represent these new aspect ratios. - Adds new cases to handle these aspect ratios while converting from user->kernel mode or vise versa. This patch was once reviewed and merged, and later reverted due to lack of DRM client protection, while adding aspect ratio bits in user modes. This is a re-spin of the series, with DRM client cap protection. The previous series can be found here: https://pw-emeril.freedesktop.org/series/10850/ Signed-off-by: Shashank Sharma Reviewed-by: Sean Paul (V2) Reviewed-by: Jose Abreu (V2) Cc: Ville Syrjala Cc: Sean Paul Cc: Jose Abreu Cc: Ankit Nautiyal V3: rebase V4: rebase V5: corrected the macro name for an aspect ratio, in a switch case. V6: rebase V7: rebase V8: rebase V9: rebase V10: rebase V11: rebase V12: rebase V13: rebase V14: rebase Acked-by: Daniel Vetter Signed-off-by: Maarten Lankhorst Link: https://patchwork.freedesktop.org/patch/msgid/1525777785-9740-11-git-send-email-ankit.k.nautiyal@intel.com

drm: Add aspect ratio parsing in DRM layer

2018-05-11T07:23:41+00:00

Current DRM layer functions don't parse aspect ratio information while converting a user mode->kernel mode or vice versa. This causes modeset to pick mode with wrong aspect ratio, eventually causing failures in HDMI compliance test cases, due to wrong VIC. This patch adds aspect ratio information in DRM's mode conversion and mode comparision functions, to make sure kernel picks mode with right aspect ratio (as per the VIC). Background: This patch was once reviewed and merged, and later reverted due to lack of DRM cap protection. This is a re-spin of this patch, this time with DRM cap protection, to avoid aspect ratio information, when the client doesn't request for it. Review link: https://pw-emeril.freedesktop.org/patch/104068/ Background discussion: https://patchwork.kernel.org/patch/9379057/ Signed-off-by: Shashank Sharma Signed-off-by: Lin, Jia Signed-off-by: Akashdeep Sharma Reviewed-by: Jim Bride (V2) Reviewed-by: Jose Abreu (V4) Cc: Ville Syrjala Cc: Jim Bride Cc: Jose Abreu Cc: Ankit Nautiyal V3: modified the aspect-ratio check in drm_mode_equal as per new flags provided by Ville. https://patchwork.freedesktop.org/patch/188043/ V4: rebase V5: rebase V6: As recommended by Ville, avoided matching of aspect-ratio in drm_fb_helper, while trying to find a common mode among connectors for the target clone mode. V7: rebase V8: rebase V9: rebase V10: rebase V11: rebase V12: rebase V13: rebase V14: rebase Acked-by: Daniel Vetter Signed-off-by: Maarten Lankhorst Link: https://patchwork.freedesktop.org/patch/msgid/1525777785-9740-10-git-send-email-ankit.k.nautiyal@intel.com

drm/modes: Introduce drm_mode_match()

2018-05-11T06:59:09+00:00

Make mode matching less confusing by allowing the caller to specify which parts of the modes should match via some flags. Signed-off-by: Ville Syrjälä Reviewed-by: Shashank Sharma Signed-off-by: Maarten Lankhorst Link: https://patchwork.freedesktop.org/patch/msgid/1525777785-9740-2-git-send-email-ankit.k.nautiyal@intel.com

drm: Fix uabi regression by allowing garbage mode->type from userspace

2018-03-23T11:51:12+00:00

Apparently xf86-video-vmware leaves the mode->type uninitialized when feeding the mode to the kernel. Thus we have no choice but to accept the garbage in. We'll just ignore any of the bits we don't want. The mode type is just a hint anyway, and more useful for the kernel->userspace direction. Reported-by: Thomas Hellstrom CC: Thomas Hellstrom Cc: Adam Jackson Cc: Alex Deucher Fixes: c6ed6dad5cfb ("drm/uapi: Validate the mode flags/type") References: https://lists.freedesktop.org/archives/dri-devel/2018-March/170213.html Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20180321211246.10152-1-ville.syrjala@linux.intel.com Tested-by: Thomas Hellstrom Reviewed-by: Maarten Lankhorst Reviewed-by: Daniel Stone

drm: Make drm_mode_vrefresh() a bit more accurate

2018-03-16T16:31:49+00:00

Do the refresh rate calculation with a single division. This gives us slightly more accurate results, especially for interlaced since we don't just double the final truncated result. We do lose one bit compared to the old way, so with an interlaced mode the new code can only handle ~2GHz instead of the ~4GHz the old code handeled. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20180313150759.27620-2-ville.syrjala@linux.intel.com Reviewed-by: Daniel Vetter

drm: Nuke the useless 'ret' variable from drm_mode_convert_umode()

2018-03-16T16:31:06+00:00

No need to store the return value in a variable since we don't have to do any unwinding. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20180313150759.27620-1-ville.syrjala@linux.intel.com Reviewed-by: Daniel Vetter