At least HiKey board can fail to bring up wireless interface again
if the interface is brought down and up with no delay inbetween.
This can be done tested with:
# while true; do ifconfig wlan0 down; ifconfig wlan0 up; done
According to Ricardo Salveti <rsalveti@xxxxxxxxxxxx>, we need to
wait between 30 - 40 ms on HiKey. This seems to happen when we
get -EBUSY returned by pm_runtime_put() basedon the check in
rpm_check_suspend_allowed(). But as it still unclear if part of
the delay needed is because of capacitance, let's always do a
at least 50 ms msleep even if no -EBUSY is returned.
Cc: Anders Roxell <anders.roxell@xxxxxxxxxx>
Cc: Eyal Reizer <eyalr@xxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Ricardo Salveti <rsalveti@xxxxxxxxxxxx>
Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Reported-by: Ricardo Salveti <rsalveti@xxxxxxxxxxxx>
Fixes: 60f36637bbbd ("wlcore: sdio: allow pm to handle sdio power")
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
Uffe, do you have some better ideas on how to fix this issue?
---
drivers/net/wireless/ti/wlcore/sdio.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/ti/wlcore/sdio.c b/drivers/net/wireless/ti/wlcore/sdio.c
--- a/drivers/net/wireless/ti/wlcore/sdio.c
+++ b/drivers/net/wireless/ti/wlcore/sdio.c
@@ -174,7 +174,7 @@ static int wl12xx_sdio_power_off(struct wl12xx_sdio_glue *glue)
{
struct sdio_func *func = dev_to_sdio_func(glue->dev);
struct mmc_card *card = func->card;
- int error;
+ int error, retries = 5;
sdio_claim_host(func);
sdio_disable_func(func);
@@ -188,6 +188,17 @@ static int wl12xx_sdio_power_off(struct wl12xx_sdio_glue *glue)
return error;
}
+ /* Wait a bit to ensure the card gets power off. Otherwise
+ * bringing interface down and up again may not power off the
+ * card inbetween. And then firmware load will fail on trying
+ * to bring the card up again. We need to wait between 30 - 40
+ * ms for this based on measurements on HiKey board.
+ */
+ do {
+ msleep(50);
+ } while (error == -EBUSY && !pm_runtime_suspended(&card->dev) &&
+ retries--);
+
return 0;
}
--
2.19.2
