4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 13e62626c578d9889ebbda7c521be5adff9bef8e ]
During "wlan-up", we are programming the FW into the WiFi-chip. However, re-programming the FW doesn't work, unless a power cycle of the WiFi-chip is made in-between the programmings.
To conform to this requirement and to fix the regression in a simple way, let's start by allowing that the SDIO card (WiFi-chip) may stay powered on (runtime resumed) when wl12xx_sdio_power_off() returns. The intent with the current code is to treat this scenario as an error, but unfortunate this doesn't work as expected, so let's fix this.
The other part is to guarantee that a power cycle of the SDIO card has been completed when wl12xx_sdio_power_on() returns, as to allow the FW programming to succeed. However, relying solely on runtime PM to deal with this isn't sufficient. For example, userspace may prevent runtime suspend via sysfs for the device that represents the SDIO card, leading to that the mmc core also keeps it powered on. For this reason, let's instead do a brute force power cycle in wl12xx_sdio_power_on().
Fixes: 728a9dc61f13 ("wlcore: sdio: Fix flakey SDIO runtime PM handling") Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Tested-by: Tony Lindgren tony@atomide.com Tested-by: Anders Roxell anders.roxell@linaro.org Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Kalle Valo kvalo@codeaurora.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/ti/wlcore/sdio.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/ti/wlcore/sdio.c b/drivers/net/wireless/ti/wlcore/sdio.c index 750bea3574ee..627df164b7b6 100644 --- a/drivers/net/wireless/ti/wlcore/sdio.c +++ b/drivers/net/wireless/ti/wlcore/sdio.c @@ -164,6 +164,12 @@ static int wl12xx_sdio_power_on(struct wl12xx_sdio_glue *glue) }
sdio_claim_host(func); + /* + * To guarantee that the SDIO card is power cycled, as required to make + * the FW programming to succeed, let's do a brute force HW reset. + */ + mmc_hw_reset(card->host); + sdio_enable_func(func); sdio_release_host(func);
@@ -174,20 +180,13 @@ 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;
sdio_claim_host(func); sdio_disable_func(func); sdio_release_host(func);
/* Let runtime PM know the card is powered off */ - error = pm_runtime_put(&card->dev); - if (error < 0 && error != -EBUSY) { - dev_err(&card->dev, "%s failed: %i\n", __func__, error); - - return error; - } - + pm_runtime_put(&card->dev); return 0; }