On Tue, 15 Jan 2019 at 19:55, Tony Lindgren <tony@xxxxxxxxxxx> wrote: > > Hi, > > * Ulf Hansson <ulf.hansson@xxxxxxxxxx> [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: Thanks for testing! > > # 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? Well, that would paper over the problem, let's see if we can avoid it. I realized that I have not invoked mmc_hw_reset() with the sdio host claimed. This could be the reason and is fixed in a v2, please try and see if that solves the "new" problem. If id doesn't, you could also convert the pm_runtime_put() to a pm_runtime_put_sync() in wl12xx_sdio_power_off() and see if that makes a difference. Kind regards Uffe
