From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Ivan Mironov <mironov.ivan@gmail.com>,
Daniel Vetter <daniel.vetter@ffwll.ch>
Subject: [PATCH 4.20 111/111] drm/fb-helper: Ignore the value of fb_var_screeninfo.pixclock
Date: Mon, 21 Jan 2019 14:43:45 +0100 [thread overview]
Message-ID: <20190121122507.181066754@linuxfoundation.org> (raw)
In-Reply-To: <20190121122455.819406896@linuxfoundation.org>
4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ivan Mironov <mironov.ivan@gmail.com>
commit 66a8d5bfb518f9f12d47e1d2dce1732279f9451e upstream.
Strict requirement of pixclock to be zero breaks support of SDL 1.2
which contains hardcoded table of supported video modes with non-zero
pixclock values[1].
To better understand which pixclock values are considered valid and how
driver should handle these values, I briefly examined few existing fbdev
drivers and documentation in Documentation/fb/. And it looks like there
are no strict rules on that and actual behaviour varies:
* some drivers treat (pixclock == 0) as "use defaults" (uvesafb.c);
* some treat (pixclock == 0) as invalid value which leads to
-EINVAL (clps711x-fb.c);
* some pass converted pixclock value to hardware (uvesafb.c);
* some are trying to find nearest value from predefined table
(vga16fb.c, video_gx.c).
Given this, I believe that it should be safe to just ignore this value if
changing is not supported. It seems that any portable fbdev application
which was not written only for one specific device working under one
specific kernel version should not rely on any particular behaviour of
pixclock anyway.
However, while enabling SDL1 applications to work out of the box when
there is no /etc/fb.modes with valid settings, this change affects the
video mode choosing logic in SDL. Depending on current screen
resolution, contents of /etc/fb.modes and resolution requested by
application, this may lead to user-visible difference (not always):
image will be displayed in a right way, but it will be aligned to the
left instead of center. There is no "right behaviour" here as well, as
emulated fbdev, opposing to old fbdev drivers, simply ignores any
requsts of video mode changes with resolutions smaller than current.
The easiest way to reproduce this problem is to install sdl-sopwith[2],
remove /etc/fb.modes file if it exists, and then try to run sopwith
from console without X. At least in Fedora 29, sopwith may be simply
installed from standard repositories.
[1] SDL 1.2.15 source code, src/video/fbcon/SDL_fbvideo.c, vesa_timings
[2] http://sdl-sopwith.sourceforge.net/
Signed-off-by: Ivan Mironov <mironov.ivan@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 79e539453b34e ("DRM: i915: add mode setting support")
Fixes: 771fe6b912fca ("drm/radeon: introduce kernel modesetting for radeon hardware")
Fixes: 785b93ef8c309 ("drm/kms: move driver specific fb common code to helper functions (v2)")
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108072353.28078-3-mironov.ivan@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/drm_fb_helper.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1690,9 +1690,14 @@ int drm_fb_helper_check_var(struct fb_va
struct drm_fb_helper *fb_helper = info->par;
struct drm_framebuffer *fb = fb_helper->fb;
- if (var->pixclock != 0 || in_dbg_master())
+ if (in_dbg_master())
return -EINVAL;
+ if (var->pixclock != 0) {
+ DRM_DEBUG("fbdev emulation doesn't support changing the pixel clock, value of pixclock is ignored\n");
+ var->pixclock = 0;
+ }
+
/*
* Changes struct fb_var_screeninfo are currently not pushed back
* to KMS, hence fail if different settings are requested.
next prev parent reply other threads:[~2019-01-21 13:51 UTC|newest]
Thread overview: 120+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-21 13:41 [PATCH 4.20 000/111] 4.20.4-stable review Greg Kroah-Hartman
2019-01-21 13:41 ` [PATCH 4.20 001/111] tty/ldsem: Wake up readers after timed out down_write() Greg Kroah-Hartman
2019-01-21 13:41 ` [PATCH 4.20 002/111] tty: Hold tty_ldisc_lock() during tty_reopen() Greg Kroah-Hartman
2019-01-21 13:41 ` [PATCH 4.20 003/111] tty: Simplify tty->count math in tty_reopen() Greg Kroah-Hartman
2019-01-21 13:41 ` [PATCH 4.20 004/111] tty: Dont hold ldisc lock in tty_reopen() if ldisc present Greg Kroah-Hartman
2019-01-21 13:41 ` [PATCH 4.20 005/111] can: gw: ensure DLC boundaries after CAN frame modification Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 006/111] netfilter: nf_conncount: replace CONNCOUNT_LOCK_SLOTS with CONNCOUNT_SLOTS Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 007/111] netfilter: nf_conncount: dont skip eviction when age is negative Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 008/111] netfilter: nf_conncount: split gc in two phases Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 009/111] netfilter: nf_conncount: restart search when nodes have been erased Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 010/111] netfilter: nf_conncount: merge lookup and add functions Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 011/111] netfilter: nf_conncount: move all list iterations under spinlock Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 012/111] netfilter: nf_conncount: speculative garbage collection on empty lists Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 013/111] netfilter: nf_conncount: fix argument order to find_next_bit Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 014/111] mmc: sdhci-msm: Disable CDR function on TX Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 015/111] arm64/kvm: consistently handle host HCR_EL2 flags Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 016/111] arm64: Dont trap host pointer auth use to EL2 Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 017/111] ipv6: fix kernel-infoleak in ipv6_local_error() Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 018/111] net: bridge: fix a bug on using a neighbour cache entry without checking its state Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 019/111] packet: Do not leak dev refcounts on error exit Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 020/111] tcp: change txhash on SYN-data timeout Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 021/111] tun: publish tfile after its fully initialized Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 022/111] net: phy: add missing phy driver features Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 023/111] net: phy: Add missing features to PHY drivers Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 024/111] net: phy: meson-gxl: Use the genphy_soft_reset callback Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 025/111] lan743x: Remove phy_read from link status change function Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 026/111] IN_BADCLASS: fix macro to actually work Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 027/111] r8169: load Realtek PHY driver module before r8169 Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 028/111] bonding: update nest level on unlink Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 029/111] ip: on queued skb use skb_header_pointer instead of pskb_may_pull Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 030/111] r8169: dont try to read counters if chip is in a PCI power-save state Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 031/111] smc: move unhash as early as possible in smc_release() Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 032/111] crypto: sm3 - fix undefined shift by >= width of value Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 033/111] crypto: caam - fix zero-length buffer DMA mapping Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 034/111] crypto: authencesn - Avoid twice completion call in decrypt path Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 035/111] crypto: ccree - convert to use crypto_authenc_extractkeys() Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 036/111] crypto: bcm " Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 037/111] crypto: authenc - fix parsing key with misaligned rta_len Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 038/111] crypto: talitos - reorder code in talitos_edesc_alloc() Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 039/111] crypto: talitos - fix ablkcipher for CONFIG_VMAP_STACK Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 040/111] xen: Fix x86 sched_clock() interface for xen Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 041/111] Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io" Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 042/111] btrfs: wait on ordered extents on abort cleanup Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 043/111] Yama: Check for pid death before checking ancestry Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 044/111] scsi: core: Synchronize request queue PM status only on successful resume Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 045/111] scsi: sd: Fix cache_type_store() Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 046/111] virtio: dont allocate vqs when names[i] = NULL Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 047/111] virtio-balloon: tweak config_changed implementation Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 048/111] mips: fix n32 compat_ipc_parse_version Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 049/111] MIPS: BCM47XX: Setup struct device for the SoC Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 050/111] MIPS: lantiq: Fix IPI interrupt handling Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 051/111] MIPS: OCTEON: fix kexec support Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 052/111] drm/i915/gvt: Fix mmap range check Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 053/111] drm/rockchip: add missing of_node_put Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 054/111] OF: properties: " Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 055/111] mfd: tps6586x: Handle interrupts on suspend Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 056/111] media: v4l: ioctl: Validate num_planes for debug messages Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 057/111] media: vim2m: only cancel work if it is for right context Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 058/111] RDMA/nldev: Dont expose unsafe global rkey to regular user Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 059/111] RDMA/vmw_pvrdma: Return the correct opcode when creating WR Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 060/111] kbuild: Disable LD_DEAD_CODE_DATA_ELIMINATION with ftrace & GCC <= 4.7 Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 061/111] kbuild: fix single target build for external module Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 062/111] kbuild: mark prepare0 as PHONY to fix external module build Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 063/111] net: dsa: realtek-smi: fix OF child-node lookup Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 064/111] pstore/ram: Avoid allocation and leak of platform data Greg Kroah-Hartman
2019-01-21 13:42 ` [PATCH 4.20 065/111] SUNRPC: Fix TCP receive code on archs with flush_dcache_page() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 066/111] powerpc/tm: Limit TM code inside PPC_TRANSACTIONAL_MEM Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 067/111] arm64: kaslr: ensure randomized quantities are clean to the PoC Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 068/111] arm64: dts: marvell: armada-ap806: reserve PSCI area Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 069/111] fbdev: offb: Fix OF node name handling Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 070/111] Disable MSI also when pcie-octeon.pcie_disable on Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 071/111] fix int_sqrt64() for very large numbers Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 072/111] omap2fb: Fix stack memory disclosure Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 073/111] media: vivid: fix error handling of kthread_run Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 074/111] media: vivid: set min width/height to a value > 0 Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 075/111] bpf: in __bpf_redirect_no_mac pull mac only if present Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 076/111] ipv6: make icmp6_send() robust against null skb->dev Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 077/111] LSM: Check for NULL cred-security on free Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 078/111] media: vb2: vb2_mmap: move lock up Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 079/111] sunrpc: handle ENOMEM in rpcb_getport_async Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 080/111] netfilter: ebtables: account ebt_table_info to kmemcg Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 081/111] block: use rcu_work instead of call_rcu to avoid sleep in softirq Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 082/111] drm/vkms: Fix plane duplicate_state Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 083/111] gpu/drm: Fix lock held when returning to user space Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 084/111] selinux: fix GPF on invalid policy Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 085/111] blockdev: Fix livelocks on loop device Greg Kroah-Hartman
2019-01-21 14:03 ` Jan Kara
2019-01-21 14:23 ` Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 086/111] sctp: allocate sctp_sockaddr_entry with kzalloc Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 087/111] tipc: fix uninit-value in in tipc_conn_rcv_sub Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 088/111] tipc: fix uninit-value in tipc_nl_compat_link_reset_stats Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 089/111] tipc: fix uninit-value in tipc_nl_compat_bearer_enable Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 090/111] tipc: fix uninit-value in tipc_nl_compat_link_set Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 091/111] tipc: fix uninit-value in tipc_nl_compat_name_table_dump Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 092/111] tipc: fix uninit-value in tipc_nl_compat_doit Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 093/111] block/loop: Dont grab "struct file" for vfs_getattr() operation Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 094/111] block/loop: Use global lock for ioctl() operation Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 095/111] loop: Fold __loop_release into loop_release Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 096/111] loop: Get rid of loop_index_mutex Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 097/111] loop: Push lo_ctl_mutex down into individual ioctls Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 098/111] loop: Split setting of lo_state from loop_clr_fd Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 099/111] loop: Push loop_ctl_mutex down into loop_clr_fd() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 100/111] loop: Push loop_ctl_mutex down to loop_get_status() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 101/111] loop: Push loop_ctl_mutex down to loop_set_status() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 102/111] loop: Push loop_ctl_mutex down to loop_set_fd() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 103/111] loop: Push loop_ctl_mutex down to loop_change_fd() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 104/111] loop: Move special partition reread handling in loop_clr_fd() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 105/111] loop: Move loop_reread_partitions() out of loop_ctl_mutex Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 106/111] loop: Fix deadlock when calling blkdev_reread_part() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 107/111] loop: Avoid circular locking dependency between loop_ctl_mutex and bd_mutex Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 108/111] loop: Get rid of nested acquisition of loop_ctl_mutex Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 109/111] loop: Fix double mutex_unlock(&loop_ctl_mutex) in loop_control_ioctl() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.20 110/111] loop: drop caches if offset or block_size are changed Greg Kroah-Hartman
2019-01-21 13:43 ` Greg Kroah-Hartman [this message]
2019-01-22 13:33 ` [PATCH 4.20 000/111] 4.20.4-stable review Naresh Kamboju
2019-01-22 16:44 ` Greg Kroah-Hartman
2019-01-22 19:24 ` Guenter Roeck
2019-01-23 6:43 ` Greg Kroah-Hartman
2019-01-22 22:25 ` shuah
2019-01-23 6:43 ` Greg Kroah-Hartman
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