On Mon, 5 Dec 2011 21:37:07 +0200 Ohad Ben-Cohen <ohad@xxxxxxxxxx> wrote: > On Mon, Dec 5, 2011 at 9:06 PM, NeilBrown <neilb@xxxxxxx> wrote: > > Challenge accepted. > > cool :) > > > Even if I don't find a better solution, this seems backwards. Sure the > > default should be that PM is enabled, but individual board can request no > > PM on MMC interfaces where it is a problem. > > I somewhat tend to pick a white listing approach, so we don't keep on > inflicting further pain on random sdio users (at least until we learn > more about the issues at hand), but I wouldn't object black listing. > > > The chip has a requirement that the reset line is held down during power-on, > > and raised shortly after (I don't know exactly how short). So if you just > > remove power and give it back, the chip doesn't come up properly. > > Well, not according to Bing Zhao from Marvell: > > http://www.mail-archive.com/linux-mmc@xxxxxxxxxxxxxxx/msg08257.html > > Though I agree that if we do find this reset line helping (and get it > to work cleanly with the help of some regulator code), the solution > might be much more robust. > > > "It *should be* perfectly fine ..." :-) > > heh, yeah :) > > > We just have to make sure the bug powers up the card properly. > > Maybe I need to create a virtual regulator that powers on the real regulator, > > then raises the reset line. I wonder how hard that is. > > Btw did you try toggling the reset line manually and see if it really helps ? > > > I'll spend some more time on this and get back to you - probably next week. > > Very cool, thanks a lot. > > Ohad. Well... I've got something to report. Firstly, this has nothing to do with power-supply to the chip. The regulator stays on the whole time and I still need to reset as some point. However there is no difference between: - power on with reset high - power on with reset low, then raise reset. So what I thought about reset before is wrong as you say. Secondly, there are two ways that I can get the wifi to work. 1/ If I keep the device from suspending until the functions have been probed, it works. To expand on this a bit: when I allow it to sleep early I see messages like: [ 315.347930] bus: 'sdio': driver_probe_device: matched device mmc1:0001:1 with driver libertas_sdio [ 315.368713] bus: 'sdio': really_probe: probing driver libertas_sdio with device mmc1:0001:1 [ 315.380859] mmc1: mmc_power_restore_host: powering up [ 315.478668] libertas_sdio: probe of mmc1:0001:1 failed with error -16 This error is ultimately caused by mmc_send_io_op_cond called from mmc_sdio_power_restore returning -110. When I force it to hold off suspend for a little while I see (starting at the same place): [ 656.189697] bus: 'sdio': driver_probe_device: matched device mmc1:0001:1 with driver libertas_sdio [ 656.212768] bus: 'sdio': really_probe: probing driver libertas_sdio with device mmc1:0001:1 [ 656.247741] libertas_sdio mmc1:0001:1: firmware: requesting libertas/sd8686_v9_helper.bin [ 656.257537] device: 'mmc1:0001:1': device_add [ 656.263580] PM: Adding info for No Bus:mmc1:0001:1 [ 656.298187] device: 'mmc1:0001:1': device_unregister [ 656.303375] PM: Removing info for No Bus:mmc1:0001:1 [ 656.322967] libertas_sdio mmc1:0001:1: firmware: requesting libertas/sd8686_v8_helper.bin [ 656.344207] device: 'mmc1:0001:1': device_add [ 656.357147] PM: Adding info for No Bus:mmc1:0001:1 [ 656.395782] device: 'mmc1:0001:1': device_unregister [ 656.407409] PM: Removing info for No Bus:mmc1:0001:1 [ 656.418579] libertas_sdio mmc1:0001:1: firmware: requesting sd8686_helper.bin [ 656.435699] device: 'mmc1:0001:1': device_add [ 656.446655] PM: Adding info for No Bus:mmc1:0001:1 [ 656.504974] device: 'mmc1:0001:1': device_unregister [ 656.511749] PM: Removing info for No Bus:mmc1:0001:1 [ 656.521148] libertas_sdio mmc1:0001:1: firmware: requesting sd8686.bin [ 656.529205] device: 'mmc1:0001:1': device_add [ 656.535095] PM: Adding info for No Bus:mmc1:0001:1 [ 656.584625] device: 'mmc1:0001:1': device_unregister [ 656.591369] PM: Removing info for No Bus:mmc1:0001:1 [ 657.384063] libertas_sdio mmc1:0001:1: (unregistered net_device): 00:19:88:3d:ff:f0, fw 9.70.3p24, cap 0x00000303 [ 657.454467] libertas_sdio mmc1:0001:1: (unregistered net_device): PREP_CMD: command 0x00a3 failed: 2 [ 657.464080] device: 'phy0': device_add But shortly there after the extra tracing I put in shows that mmc_power_off is called, then mmc_sdio_power_restore calls mmc_send_io_op_cond which again returns -110, but now it isn't a problem and the wifi chip keeps working. So maybe the fact that we error-out in the first case is a problem?? I found that if I pull the reset line down and then let it back up then it all works. mmc_send_io_op_cond never returns -110. Specifically I first put the reset ( gpio_set_value_cansleep(212, 0); mmc_delay(10); gpio_set_value_cansleep(212, 1); mmc_delay(10); ) in mmc_power_up just before the final "mmc_host_clk_release(host);" That worked. I then tried to be clever and defined a 'remux' routine (called from hsmmc23_before_set_reg from omap_hsmmc_235_set_power from omap_hsmmc_set_io from mmc_power_up), and that works too. So that allows me to reset the wifi chip at the right time with only changes to my 'board' file. However I don't think a reset was the intention of 'remux' so this solution feels a little dirty. My thought is that something in the suspend/resume sequence is confusing the wifi chip and it needs a reset to get out of it. However if I just make mmc_power_off a no-op (insert an early 'return') it still fails. I tried poking around and commenting out other function calls but only ever manage to break it more, never to fix it :-( So I have run out of ideas. I can make it work by reseting the chip during mmc_power_up but I have no idea what is causing the chip to need a reset. All I know is that it isn't the power-supply being removed. If you or anyone would like to suggest anything else I could test, or any interesting information that I could extract that might be helpful, then I'm happy to give that a go (with the understanding that the turn-around time could easily be a week or more). However for now I think I'll go with my 'remux' hack. Thanks, NeilBrown
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