At least on wl12xx, reading the MAC after boot can fail with a warning at drivers/net/wireless/ti/wlcore/sdio.c:78 wl12xx_sdio_raw_read. The failed call comes from wl12xx_get_mac() that wlcore_nvs_cb() calls after request_firmware_work_func(). After the error, no wireless interface is created. Reloading the wl12xx module makes the interface work. Turns out the wlan controller can be in a low-power ELP state after the boot from the bootloader or kexec, and needs to be woken up first. Let's wake the hardware and add a sleep after that similar to wl12xx_pre_boot() is already doing. Note that a similar issue could exist for wl18xx, but I have not seen it so far. And a search for wl18xx_get_mac and wl12xx_sdio_raw_read did not produce similar errors. Cc: Carl Philipp Klemm <philipp@xxxxxxxx> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> --- drivers/net/wireless/ti/wl12xx/main.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/wireless/ti/wl12xx/main.c b/drivers/net/wireless/ti/wl12xx/main.c --- a/drivers/net/wireless/ti/wl12xx/main.c +++ b/drivers/net/wireless/ti/wl12xx/main.c @@ -1503,6 +1503,13 @@ static int wl12xx_get_fuse_mac(struct wl1271 *wl) u32 mac1, mac2; int ret; + /* Device may be in ELP from the bootloader or kexec */ + ret = wlcore_write32(wl, WL12XX_WELP_ARM_COMMAND, WELP_ARM_COMMAND_VAL); + if (ret < 0) + goto out; + + usleep_range(500000, 700000); + ret = wlcore_set_partition(wl, &wl->ptable[PART_DRPW]); if (ret < 0) goto out; -- 2.31.1
