> Date: Sat, 23 Nov 2024 18:15:51 +0300
> From: Paul Fertser <fercerpav@gmail.com>
> 
> Many board DT files specify this property so it must be essential for
> reliable hardware bringup.
> 
> This seems to be completely fixing the intermittent boot problems on
> Pinebook Pro (RK3399 with AzureWave AW-CM256SM SDIO WiFi module) which
> manifested as a hang after showing "bwfm_sdio_buf_write: error
> 60". I've tried great many reboots and power cycling with varying
> amount of time between turning on and off and couldn't reproduce the
> issue anymore after making this change. I guess this might help with
> Raspberry Pi 3 WiFi too (can not test since I do not have that
> hardware handy).
> 
> The fix is kind of surprising since the timeout error occurs much
> later after powering on the module, during firmware activation, here's
> the back trace in case it might be useful:
> 
> Starting stack trace...
> locore0.S() at dwmmc_exec_command+0x538
> 	[.../sys/dev/fdt/dwmmc.c:1043]
> dwmmc_exec_command() at sdmmc_io_rw_extended+0x1e0
> 	[.../sys/dev/sdmmc/sdmmc_io.c:443]
> sdmmc_io_rw_extended() at bwfm_sdio_ram_read_write+0x160
> 	[.../sys/dev/sdmmc/if_bwfm_sdio.c:903]
> bwfm_sdio_ram_read_write() at bwfm_sdio_buscore_activate+0x60
> 	[.../sys/dev/sdmmc/if_bwfm_sdio.c:1052]
> bwfm_sdio_buscore_activate() at bwfm_chip_set_active+0xf0
> 	[.../sys/dev/ic/bwfm.c:1277]
> bwfm_chip_set_active() at bwfm_sdio_load_microcode+0x24c
> 	[.../sys/dev/sdmmc/if_bwfm_sdio.c:545]
> bwfm_sdio_load_microcode() at bwfm_sdio_preinit+0x1f0
> 	[.../sys/dev/sdmmc/if_bwfm_sdio.c:421]
> bwfm_sdio_preinit() at bwfm_attachhook+0x30
> 	[.../sys/dev/ic/bwfm.c:238]
> bwfm_attachhook() at config_process_deferred_mountroot+0x58
> 	[.../sys/kern/subr_autoconf.c:763]
> config_process_deferred_mountroot() at main+0x5f8
> 	[.../sys/kern/init_main.c:528]
> main() at virtdone+0x70
> End of stack trace.    
> bwfm_sdio_buf_write: error 60

Thanks!  Committed with a tiny cosmetic change (reverse christmas tree
sorting of the local variables).

> ---
> 
> diff --git sys/dev/fdt/dwmmc.c sys/dev/fdt/dwmmc.c
> index a66318fb7926..5d6f22a4a28b 100644
> --- sys/dev/fdt/dwmmc.c
> +++ sys/dev/fdt/dwmmc.c
> @@ -1254,6 +1254,7 @@ dwmmc_pwrseq_post(uint32_t phandle)
>  	uint32_t *gpios, *gpio;
>  	int node;
>  	int len;
> +	int post_delay;
>  
>  	node = OF_getnodebyphandle(phandle);
>  	if (node == 0)
> @@ -1275,5 +1276,9 @@ dwmmc_pwrseq_post(uint32_t phandle)
>  		gpio = gpio_controller_next_pin(gpio);
>  	}
>  
> +	post_delay = OF_getpropint(node, "post-power-on-delay-ms", 0);
> +	if (post_delay)
> +		delay(post_delay * 1000);
> +
>  	free(gpios, M_TEMP, len);
>  }
> 
>