| Message ID | 20210118150656.796584-1-geert+renesas@glider.be |
|---|---|
| Headers | show |
| Series | sh_eth: Fix reboot crash | expand |
On Mon, Jan 18, 2021 at 04:06:56PM +0100, Geert Uytterhoeven wrote: > Wolfram reports that his R-Car H2-based Lager board can no longer be > rebooted in v5.11-rc1, as it crashes with an imprecise external abort. > The issue can be reproduced on other boards (e.g. Koelsch with R-Car > M2-W) too, if CONFIG_IP_PNP is disabled, and the Ethernet interface is > down at reboot time: > > Unhandled fault: imprecise external abort (0x1406) at 0x00000000 > pgd = (ptrval) > [00000000] *pgd=422b6835, *pte=00000000, *ppte=00000000 > Internal error: : 1406 [#1] ARM > Modules linked in: > CPU: 0 PID: 1105 Comm: init Tainted: G W 5.10.0-rc1-00402-ge2f016cf7751 #1048 > Hardware name: Generic R-Car Gen2 (Flattened Device Tree) > PC is at sh_mdio_ctrl+0x44/0x60 > LR is at sh_mmd_ctrl+0x20/0x24 > ... > Backtrace: > [<c0451f30>] (sh_mdio_ctrl) from [<c0451fd4>] (sh_mmd_ctrl+0x20/0x24) > r7:0000001f r6:00000020 r5:00000002 r4:c22a1dc4 > [<c0451fb4>] (sh_mmd_ctrl) from [<c044fc18>] (mdiobb_cmd+0x38/0xa8) > [<c044fbe0>] (mdiobb_cmd) from [<c044feb8>] (mdiobb_read+0x58/0xdc) > r9:c229f844 r8:c0c329dc r7:c221e000 r6:00000001 r5:c22a1dc4 r4:00000001 > [<c044fe60>] (mdiobb_read) from [<c044c854>] (__mdiobus_read+0x74/0xe0) > r7:0000001f r6:00000001 r5:c221e000 r4:c221e000 > [<c044c7e0>] (__mdiobus_read) from [<c044c9d8>] (mdiobus_read+0x40/0x54) > r7:0000001f r6:00000001 r5:c221e000 r4:c221e458 > [<c044c998>] (mdiobus_read) from [<c044d678>] (phy_read+0x1c/0x20) > r7:ffffe000 r6:c221e470 r5:00000200 r4:c229f800 > [<c044d65c>] (phy_read) from [<c044d94c>] (kszphy_config_intr+0x44/0x80) > [<c044d908>] (kszphy_config_intr) from [<c044694c>] (phy_disable_interrupts+0x44/0x50) > r5:c229f800 r4:c229f800 > [<c0446908>] (phy_disable_interrupts) from [<c0449370>] (phy_shutdown+0x18/0x1c) > r5:c229f800 r4:c229f804 > [<c0449358>] (phy_shutdown) from [<c040066c>] (device_shutdown+0x168/0x1f8) > [<c0400504>] (device_shutdown) from [<c013de44>] (kernel_restart_prepare+0x3c/0x48) > r9:c22d2000 r8:c0100264 r7:c0b0d034 r6:00000000 r5:4321fedc r4:00000000 > [<c013de08>] (kernel_restart_prepare) from [<c013dee0>] (kernel_restart+0x1c/0x60) > [<c013dec4>] (kernel_restart) from [<c013e1d8>] (__do_sys_reboot+0x168/0x208) > r5:4321fedc r4:01234567 > [<c013e070>] (__do_sys_reboot) from [<c013e2e8>] (sys_reboot+0x18/0x1c) > r7:00000058 r6:00000000 r5:00000000 r4:00000000 > [<c013e2d0>] (sys_reboot) from [<c0100060>] (ret_fast_syscall+0x0/0x54) > > As of commit e2f016cf775129c0 ("net: phy: add a shutdown procedure"), > system reboot calls phy_disable_interrupts() during shutdown. As this > happens unconditionally, the PHY registers may be accessed while the > device is suspended, causing undefined behavior, which may crash the > system. > > Fix this by wrapping the PHY bitbang accessors in the sh_eth driver by > wrappers that take care of Runtime PM, to resume the device when needed. > > Reported-by: Wolfram Sang <wsa+renesas@sang-engineering.com> > Suggested-by: Andrew Lunn <andrew@lunn.ch> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Thanks for debugging and fixing this, Geert!
Hello: This series was applied to netdev/net.git (refs/heads/master): On Mon, 18 Jan 2021 16:06:54 +0100 you wrote: > Hi, > > This patch fixes a regression v5.11-rc1, where rebooting while a sh_eth > device is not opened will cause a crash. > > Changes compared to v1: > - Export mdiobb_{read,write}(), > - Call mdiobb_{read,write}() now they are exported, > - Use mii_bus.parent to avoid bb_info.dev copy, > - Drop RFC state. > > [...] Here is the summary with links: - [net,v2,1/2] mdio-bitbang: Export mdiobb_{read,write}() https://git.kernel.org/netdev/net/c/8eed01b5ca9c - [net,v2,2/2] sh_eth: Make PHY access aware of Runtime PM to fix reboot crash https://git.kernel.org/netdev/net/c/02cae02a7de1 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
Hi, This patch fixes a regression v5.11-rc1, where rebooting while a sh_eth device is not opened will cause a crash. Changes compared to v1: - Export mdiobb_{read,write}(), - Call mdiobb_{read,write}() now they are exported, - Use mii_bus.parent to avoid bb_info.dev copy, - Drop RFC state. Alternatively, mdio-bitbang could provide Runtime PM-aware wrappers itself, and use them either manually (through a new parameter to alloc_mdio_bitbang(), or a new alloc_mdio_bitbang_*() function), or automatically (e.g. if pm_runtime_enabled() returns true). Note that the latter requires a "struct device *" parameter to operate on. Currently there are only two drivers that call alloc_mdio_bitbang() and use Runtime PM: the Renesas sh_eth and ravb drivers. This series fixes the former, while the latter is not affected (it keeps the device powered all the time between driver probe and driver unbind, and changing that seems to be non-trivial). Thanks for your comments! Geert Uytterhoeven (2): net: mdio-bitbang: Export mdiobb_{read,write}() sh_eth: Make PHY access aware of Runtime PM to fix reboot crash drivers/net/ethernet/renesas/sh_eth.c | 26 ++++++++++++++++++++++++++ drivers/net/mdio/mdio-bitbang.c | 6 ++++-- include/linux/mdio-bitbang.h | 3 +++ 3 files changed, 33 insertions(+), 2 deletions(-)