Messages in this thread | | | Date | Tue, 15 Jan 2019 10:55:09 -0800 | From | Tony Lindgren <> | Subject | Re: [PATCH] wlcore: sdio: Fixup power on/off sequence |
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Hi,
* Ulf Hansson <ulf.hansson@linaro.org> [190115 15:04]: > 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().
Thanks this looks good.. But looks like udelay 20000 is needed with:
# while [ 1 ]; do ifconfig wlan0 down; usleep 20000; \ ifconfig wlan0 up; done
Otherwise I get the following on warning pandaboard-es:
WARNING: CPU: 0 PID: 1770 at drivers/bus/omap_l3_noc.c:147 l3_interrupt_handler+0x2f8/0x388 44000000.ocp:L3 Custom Error: MASTER MPU TARGET L4PER2 (Read): Data Access in User mode during Functional access
Meaning that we access registers while not clocked somewhere. I think that warning is different from the earlier errors though :) And we could add a msleep(50) to the end to mostly avoid it until we have a better fix available?
Regards,
Tony
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