Hi Claudiu, On Fri, 9 Jan 2026 11:49:23 +0200 Claudiu Beznea <[email protected]> wrote:
> Hi, Hugo, > > On 1/8/26 17:53, Hugo Villeneuve wrote: > > Hi Claudiu, > > > > On Thu, 8 Jan 2026 11:12:54 +0200 > > Claudiu Beznea <[email protected]> wrote: > > > >> Hi, Hugo, > >> > >> On 1/7/26 23:48, Hugo Villeneuve wrote: > >>> Hi, > >>> when issuing a reboot command, I encounter the following kernel panic: > >>> > >>> [ 36.183478] SError Interrupt on CPU1, code 0x00000000be000011 -- SError > >>> [ 36.183492] CPU: 1 UID: 0 PID: 1 Comm: systemd-shutdow Tainted: G M > >>> 6.19.0-rc4-arm64-renesas-00019-g067a81578add #62 NONE > >>> [ 36.183504] Tainted: [M]=MACHINE_CHECK > >>> [ 36.183507] Hardware name: Gecko ECO2 nxtpad (DT) > >>> [ 36.183512] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS > >>> BTYPE=--) > >>> [ 36.183519] pc : rzg2l_mipi_dsi_host_transfer+0x114/0x458 > >>> [ 36.183538] lr : rzg2l_mipi_dsi_host_transfer+0x98/0x458 > >>> [ 36.183547] sp : ffff8000813db860 > >>> [ 36.183550] x29: ffff8000813db890 x28: ffff800080c602c0 x27: > >>> ffff000009dd7450 > >>> [ 36.183563] x26: ffff800080c5fcc0 x25: ffff000009dd7450 x24: > >>> ffff800080e1f7a8 > >>> [ 36.183573] x23: ffff000009dd7400 x22: 0000000000000000 x21: > >>> ffff000009dd7430 > >>> [ 36.183582] x20: ffff8000813db8e8 x19: 0000000002050028 x18: > >>> 00000000ffffffff > >>> [ 36.183592] x17: 0000000000000000 x16: 0000000000000000 x15: > >>> ffff8000813db220 > >>> [ 36.183602] x14: 0000000000000000 x13: ffff800081255bc0 x12: > >>> 00000000000009a2 > >>> [ 36.183611] x11: 0000000000000336 x10: ffff8000812b28d0 x9 : > >>> ffff800081255bc0 > >>> [ 36.183621] x8 : ffff800081399000 x7 : ffff00000a042600 x6 : > >>> 0000000000000000 > >>> [ 36.183631] x5 : 0000000000000805 x4 : 0000000002000000 x3 : > >>> 0000000000000028 > >>> [ 36.183640] x2 : 0000000049627000 x1 : ffff800080c60b40 x0 : > >>> ffff800081780000 > >>> [ 36.183652] Kernel panic - not syncing: Asynchronous SError Interrupt > >>> [ 36.183657] CPU: 1 UID: 0 PID: 1 Comm: systemd-shutdow Tainted: G M > >>> 6.19.0-rc4-arm64-renesas-00019-g067a81578add #62 NONE > >>> [ 36.183665] Tainted: [M]=MACHINE_CHECK > >>> [ 36.183668] Hardware name: devboard1 (DT) > >>> [ 36.183672] Call trace: > >>> [ 36.183675] show_stack+0x18/0x24 (C) > >>> [ 36.183692] dump_stack_lvl+0x34/0x8c > >>> [ 36.183702] dump_stack+0x18/0x24 > >>> [ 36.183708] vpanic+0x314/0x35c > >>> [ 36.183716] nmi_panic+0x0/0x64 > >>> [ 36.183722] add_taint+0x0/0xbc > >>> [ 36.183728] arm64_serror_panic+0x70/0x80 > >>> [ 36.183735] do_serror+0x28/0x68 > >>> [ 36.183742] el1h_64_error_handler+0x34/0x50 > >>> [ 36.183751] el1h_64_error+0x6c/0x70 > >>> [ 36.183758] rzg2l_mipi_dsi_host_transfer+0x114/0x458 (P) > >>> [ 36.183770] mipi_dsi_device_transfer+0x44/0x58 > >>> [ 36.183781] mipi_dsi_dcs_set_display_off_multi+0x9c/0xc4 > >>> [ 36.183792] ili9881c_unprepare+0x38/0x88 > >>> [ 36.183802] drm_panel_unprepare+0xbc/0x108 > >>> [ 36.183814] panel_bridge_atomic_post_disable+0x50/0x60 > >>> [ 36.183823] drm_atomic_bridge_call_post_disable+0x24/0x4c > >>> [ 36.183835] drm_atomic_bridge_chain_post_disable+0xa8/0x100 > >>> [ 36.183845] drm_atomic_helper_commit_modeset_disables+0x2fc/0x5f8 > >>> [ 36.183856] drm_atomic_helper_commit_tail_rpm+0x24/0x7c > >>> [ 36.183865] commit_tail+0xa4/0x18c > >>> [ 36.183874] drm_atomic_helper_commit+0x17c/0x194 > >>> [ 36.183884] drm_atomic_commit+0x8c/0xcc > >>> [ 36.183892] drm_atomic_helper_disable_all+0x200/0x210 > >>> [ 36.183901] drm_atomic_helper_shutdown+0xa8/0x150 > >>> [ 36.183911] rzg2l_du_shutdown+0x18/0x24 > >>> [ 36.183920] platform_shutdown+0x24/0x34 > >>> [ 36.183931] device_shutdown+0x128/0x284 > >>> [ 36.183938] kernel_restart+0x44/0xa4 > >>> [ 36.183950] __do_sys_reboot+0x178/0x270 > >>> [ 36.183959] __arm64_sys_reboot+0x24/0x30 > >>> [ 36.183968] invoke_syscall.constprop.0+0x50/0xe4 > >>> [ 36.183979] do_el0_svc+0x40/0xc0 > >>> [ 36.183988] el0_svc+0x3c/0x164 > >>> [ 36.183995] el0t_64_sync_handler+0xa0/0xe4 > >>> [ 36.184002] el0t_64_sync+0x198/0x19c > >>> [ 36.184020] Kernel Offset: disabled > >>> [ 36.184022] CPU features: 0x200000,00020001,4000c501,0400720b > >>> [ 36.184028] Memory Limit: none > >>> [ 36.495305] ---[ end Kernel panic - not syncing: Asynchronous SError > >>> Interrupt ]--- > >>> > >>> The problem is present since linux-6.18-rc1, but not in linux-6.17. I > >>> also confirm the bug is present in linux-6.19-rc4. > >>> > >>> The bug seems to be happening in rzg2l_mipi_dsi_host_transfer(). > >>> > >>> After bisecting, here is the first bad commit: > >>> > >>> commit 56de5e305d4b ("clk: renesas: r9a07g044: Add MSTOP for > >>> RZ/G2L") > >>> > >>> Reverting this change makes the bug disappear. > >>> > >>> My limited understanding seems to indicate that the MIPI/DSI host may > >>> no longer be available/on when the panel tries to send MIPI/DSI > >>> commands in ili9881c_unprepare(), maybe because the MIPI/DSI clock has > >>> been stopped... > >>> > >>> The exact same board with two other panels (jd9365da and st7703) doesn't > >>> have the bug. > >> > >> Could you please provide the output of command: > >> > >> cat /sys/kernel/debug/mstop > >> > >> for both cases? > > > > Here it is for the panel which has the bug: > > > > ---------------------------------- > > MSTOP > > clk ------------------------- > > clk_name cnt cnt off val shared > > -------- ----- ----- ----- ------ ------ > > gic 1 1 0xb80 0x0 > > ia55_clk 2 2 0xb70 0x0 ia55_pclk ia55_clk > > ia55_pclk 1 2 0xb70 0x0 ia55_pclk ia55_clk > > dmac_aclk 2 1 0xb80 0x0 > > dmac_pclk 1 1 0xb80 0x0 > > ostm0_pclk 0 0 0xb7c 0x10 > > ostm1_pclk 1 1 0xb7c 0x0 > > ostm2_pclk 1 1 0xb7c 0x0 > > mtu_x_mck 0 0 0xb64 0x4 > > gpt_pclk 1 1 0xb64 0x0 > > poeg_a_clkp 0 0 0xb64 0x20 > > poeg_b_clkp 0 0 0xb64 0x40 > > poeg_c_clkp 0 0 0xb64 0x80 > > poeg_d_clkp 0 0 0xb64 0x100 > > wdt0_pclk 1 2 0xb7c 0x0 wdt0_pclk wdt0_clk > > wdt0_clk 1 2 0xb7c 0x0 wdt0_pclk wdt0_clk > > wdt1_pclk 0 0 0xb7c 0x8 wdt1_pclk wdt1_clk > > wdt1_clk 0 0 0xb7c 0x8 wdt1_pclk wdt1_clk > > spi_clk2 0 0 0xb64 0x2 spi_clk2 spi_clk > > spi_clk 0 0 0xb64 0x2 spi_clk2 spi_clk > > sdhi0_imclk 1 4 0xb6c 0x0 sdhi0_imclk sdhi0_imclk2 > > sdhi0_clk_hs sdhi0_aclk > > sdhi0_imclk2 2 4 0xb6c 0x0 sdhi0_imclk sdhi0_imclk2 > > sdhi0_clk_hs sdhi0_aclk > > sdhi0_clk_hs 1 4 0xb6c 0x0 sdhi0_imclk sdhi0_imclk2 > > sdhi0_clk_hs sdhi0_aclk > > sdhi0_aclk 1 4 0xb6c 0x0 sdhi0_imclk sdhi0_imclk2 > > sdhi0_clk_hs sdhi0_aclk > > sdhi1_imclk 0 0 0xb6c 0x2 sdhi1_imclk sdhi1_imclk2 > > sdhi1_clk_hs sdhi1_aclk > > sdhi1_imclk2 0 0 0xb6c 0x2 sdhi1_imclk sdhi1_imclk2 > > sdhi1_clk_hs sdhi1_aclk > > sdhi1_clk_hs 0 0 0xb6c 0x2 sdhi1_imclk sdhi1_imclk2 > > sdhi1_clk_hs sdhi1_aclk > > sdhi1_aclk 0 0 0xb6c 0x2 sdhi1_imclk sdhi1_imclk2 > > sdhi1_clk_hs sdhi1_aclk > > gpu_clk 1 1 0xb80 0x0 > > cru_sysclk 0 0 0xb78 0x8 cru_sysclk cru_vclk cru_pclk > > cru_aclk > > cru_vclk 0 0 0xb78 0x8 cru_sysclk cru_vclk cru_pclk > > cru_aclk > > cru_pclk 0 0 0xb78 0x8 cru_sysclk cru_vclk cru_pclk > > cru_aclk > > cru_aclk 0 0 0xb78 0x8 cru_sysclk cru_vclk cru_pclk > > cru_aclk > > > dsi_pll_clk 1 6 0xb78 0x0 dsi_pll_clk dsi_sys_clk > > dsi_aclk dsi_pclk dsi_vclk dsi_lpclk > > dsi_sys_clk 1 6 0xb78 0x0 dsi_pll_clk dsi_sys_clk > > dsi_aclk dsi_pclk dsi_vclk dsi_lpclk > > dsi_aclk 1 6 0xb78 0x0 dsi_pll_clk dsi_sys_clk > > dsi_aclk dsi_pclk dsi_vclk dsi_lpclk > > dsi_pclk 1 6 0xb78 0x0 dsi_pll_clk dsi_sys_clk > > dsi_aclk dsi_pclk dsi_vclk dsi_lpclk > > dsi_vclk 1 6 0xb78 0x0 dsi_pll_clk dsi_sys_clk > > dsi_aclk dsi_pclk dsi_vclk dsi_lpclk > > dsi_lpclk 1 6 0xb78 0x0 dsi_pll_clk dsi_sys_clk > > dsi_aclk dsi_pclk dsi_vclk dsi_lpclk > > I was expected the MSTOP for these to be set to anythong other than 0x0 > here. But I presume, they are somehow set in the reboot process before > exectution reach rzg2l_mipi_dsi_host_transfer(). To be honest, I don't > know the rz-du code. Maybe Biju can shed some light on this? > > [...] > > > > > I do not have acces to the other panels for the moment to run the same > > command. > > > > > >> Also, could you please check if the following diff solves your problem: > >> > >> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c > >> b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c > >> index 5edd45424562..62957632a96f 100644 > >> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c > >> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c > >> @@ -1282,6 +1282,10 @@ static ssize_t > >> rzg2l_mipi_dsi_host_transfer(struct mipi_dsi_host *host, > >> value |= SQCH0DSC0AR_FMT_SHORT; > >> } > >> > >> + ret = pm_runtime_resume_and_get(dsi->dev); > >> + if (ret) > >> + return ret; > >> + > >> rzg2l_mipi_dsi_link_write(dsi, SQCH0DSC0AR, value); > >> > >> /* > >> @@ -1322,6 +1326,8 @@ static ssize_t rzg2l_mipi_dsi_host_transfer(struct > >> mipi_dsi_host *host, > >> ret = packet.payload_length; > >> } > >> > >> + pm_runtime_put(dsi->dev); > >> + > >> return ret; > >> } > > > > I confirm that it fixes the bug, altought I assume this is just for testing > > and is not the "proper" fix. > > To me, this, or something similar should be done anyway. Previously it > used to work because there was no MSTOP support available. > > The MSTOP is now set when all of the clocks sharing it are disabled. > With the MSTOP set, any master accessing a HW block that has MSTOP set > will get sync abort. That wasn't the case previously, when the HW > registers could have been accessed w/o generating such exeception. > > Thank you, > Claudiu > -- Hugo Villeneuve
