On Wed, Feb 12, 2025 at 04:46:28PM +0100, Alexis Lothoré wrote:
> If the wlan interface exposed by wilc driver has power save enabled
> (either explicitly with iw dev wlan set power_save on, or because
> kernel is built with CONFIG_CFG80211_DEFAULT_PS), it will send a power
> management command to the wlan firmware when corresponding interface is
> brought up. The bluetooth part, if used, is supposed to work
> independently from the WLAN CPU. Unfortunately, this power save
> management, if applied by the WLAN side, disrupts bluetooth operations
> (the bluetooth CPU does not answer any command anymore on the UART
> interface)
>
> Make sure that the bluetooth part can work independently by disabling
> power save in wlan firmware when bluetooth is in use.
>
> Signed-off-by: Alexis Lothoré <alexis.lothore@xxxxxxxxxxx>
> ---
> drivers/net/wireless/microchip/wilc1000/bt.c | 29 +++++++++++++++++++---
> drivers/net/wireless/microchip/wilc1000/cfg80211.c | 5 +++-
> drivers/net/wireless/microchip/wilc1000/netdev.h | 3 +++
> 3 files changed, 33 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/wireless/microchip/wilc1000/bt.c b/drivers/net/wireless/microchip/wilc1000/bt.c
> index b0f68a5479a5bd6f70e2390a35512037dc6c332b..f0eb5fb506eddf0f6f4f3f0b182eaa650c1c7a87 100644
> --- a/drivers/net/wireless/microchip/wilc1000/bt.c
> +++ b/drivers/net/wireless/microchip/wilc1000/bt.c
> @@ -7,6 +7,7 @@
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> #include <net/wilc.h>
> +#include "cfg80211.h"
> #include "netdev.h"
> #include "wlan_if.h"
> #include "wlan.h"
> @@ -261,22 +262,36 @@ static int wilc_bt_start(struct wilc *wilc)
> int wilc_bt_init(void *wilc_wl_priv)
> {
> struct wilc *wilc = (struct wilc *)wilc_wl_priv;
> + struct wilc_vif *vif;
> int ret;
>
> + wilc->bt_enabled = true;
> +
> if (!wilc->hif_func->hif_is_init(wilc)) {
> dev_info(wilc->dev, "Initializing bus before starting BT");
> acquire_bus(wilc, WILC_BUS_ACQUIRE_ONLY);
> ret = wilc->hif_func->hif_init(wilc, false);
> release_bus(wilc, WILC_BUS_RELEASE_ONLY);
> - if (ret)
> + if (ret) {
> + wilc->bt_enabled = false;
> return ret;
> + }
> }
>
> + /* Power save feature managed by WLAN firmware may disrupt
> + * operations from the bluetooth CPU, so disable it while bluetooth
> + * is in use (if enabled, it will be enabled back when bluetooth is
> + * not used anymore)
> + */
> + vif = wilc_get_wl_to_vif(wilc);
> + if (wilc->power_save_mode && wilc_set_power_mgmt(vif, false))
> + goto hif_deinit;
Hi Alexis,
Jumping to hif_deinit will result in the function returning ret.
But ret may not not be initialised until a few lines below.
Flagged by Smatch.
> +
> mutex_lock(&wilc->radio_fw_start);
> ret = wilc_bt_power_up(wilc);
> if (ret) {
> dev_err(wilc->dev, "Error powering up bluetooth chip\n");
> - goto hif_deinit;
> + goto reenable_power_save;
> }
> ret = wilc_bt_firmware_download(wilc);
> if (ret) {
> @@ -293,10 +308,14 @@ int wilc_bt_init(void *wilc_wl_priv)
>
> power_down:
> wilc_bt_power_down(wilc);
> -hif_deinit:
> +reenable_power_save:
> + if (wilc->power_save_mode_request)
> + wilc_set_power_mgmt(vif, true);
> mutex_unlock(&wilc->radio_fw_start);
> +hif_deinit:
> if (!wilc->initialized)
> wilc->hif_func->hif_deinit(wilc);
> + wilc->bt_enabled = false;
> return ret;
> }
> EXPORT_SYMBOL(wilc_bt_init);
...
