With newer versions of GCC, there is a panic in da850_evm_config_emac() when booting multi_v5_defconfig in QEMU under the palmetto-bmc machine:
Unable to handle kernel NULL pointer dereference at virtual address 00000020 pgd = (ptrval) [00000020] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.15.0 #1 Hardware name: Generic DT based system PC is at da850_evm_config_emac+0x1c/0x120 LR is at do_one_initcall+0x50/0x1e0
The emac_pdata pointer in soc_info is NULL because davinci_soc_info only gets populated on davinci machines but da850_evm_config_emac() is called on all machines via device_initcall().
Move the rmii_en assignment below the machine check so that it is only dereferenced when running on a supported SoC.
Cc: stable@vger.kernel.org Fixes: bae105879f2f ("davinci: DA850/OMAP-L138 EVM: implement autodetect of RMII PHY") Link: https://lore.kernel.org/r/YcS4xVWs6bQlQSPC@archlinux-ax161/ Reviewed-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Nathan Chancellor nathan@kernel.org --- arch/arm/mach-davinci/board-da850-evm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mach-davinci/board-da850-evm.c b/arch/arm/mach-davinci/board-da850-evm.c index 428012687a80..7f7f6bae21c2 100644 --- a/arch/arm/mach-davinci/board-da850-evm.c +++ b/arch/arm/mach-davinci/board-da850-evm.c @@ -1101,11 +1101,13 @@ static int __init da850_evm_config_emac(void) int ret; u32 val; struct davinci_soc_info *soc_info = &davinci_soc_info; - u8 rmii_en = soc_info->emac_pdata->rmii_en; + u8 rmii_en;
if (!machine_is_davinci_da850_evm()) return 0;
+ rmii_en = soc_info->emac_pdata->rmii_en; + cfg_chip3_base = DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP3_REG);
val = __raw_readl(cfg_chip3_base);
base-commit: a7904a538933c525096ca2ccde1e60d0ee62c08e