Javier, On Mon, Feb 23, 2015 at 8:33 AM, Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx> wrote: > Hello Doug, > > On 02/20/2015 09:31 PM, Doug Anderson wrote: >> We've seen problems on some WiFi modules where we seem to send a CMD53 >> (which requires the data lines) while the module is asserting busy. >> We shouldn't do that. >> >> The Designware Databook says that before issuing a new data transfer >> command we should check for busy, so that's what we'll do. >> > > I tried $subject along with patches: > > * mmc: dw_mmc: Make sure we only adjust the clock when power is on > https://patchwork.kernel.org/patch/5858261/ > > * mmc: dw_mmc: Give a good reset after we give power > https://patchwork.kernel.org/patch/5858281/ > > but unfortunately these don't solve the "Timeout sending command" error > that I got when trying to enable the WiFi module on the Peach Pit and Pi: > > [ 5.332103] dwmmc_exynos 12210000.mmc: Busy; trying anyway > [ 5.336110] mmc_host mmc2: Timeout sending command (cmd 0x202000 arg 0x0 status 0x0) > >> We'll leverage the existing dw_mmc knowledge about whether it should >> wait for the previous command to finish to know whether we should >> check for busy before sending the command. This means we won't end up >> incorrectly waiting for things like CMD52 (SDIO) or CMD13 (SD) which >> don't use the data line. >> >> Note that this also has the advantage of making sure that we don't >> change the clock while the card is busy, too. >> > > The timeout happens in this case: > > mmc_rescan() > mmc_attach_sdio() > mmc_sdio_init_card() > dw_mci_init_card() > mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | > SDMMC_CMD_PRV_DAT_WAIT, 0); > > which should be covered by your patch since the SDMMC_CMD_PRV_DAT_WAIT flag > is set but SDMMC_STATUS_BUSY bit is not cleared and mci_send_cmd() timeouts > when sending the command to the controller. > >> >> +static void dw_mci_wait_while_busy(struct dw_mci *host, u32 cmd_flags) >> +{ >> + unsigned long timeout = jiffies + msecs_to_jiffies(500); >> + >> + /* >> + * Databook says that before issuing a new data transfer command >> + * we need to check to see if the card is busy. Data transfer commands >> + * all have SDMMC_CMD_PRV_DAT_WAIT set, so we'll key off that. >> + * >> + * ...also allow sending for SDMMC_CMD_VOLT_SWITCH where busy is >> + * expected. >> + */ >> + if ((cmd_flags & SDMMC_CMD_PRV_DAT_WAIT) && >> + !(cmd_flags & SDMMC_CMD_VOLT_SWITCH)) { >> + while (mci_readl(host, STATUS) & SDMMC_STATUS_BUSY) { >> + if (time_after(jiffies, timeout)) { >> + /* Command will fail; we'll pass error then */ >> + dev_err(host->dev, "Busy; trying anyway\n"); > > Addy's "mmc: dw_mmc: fix bug that cause 'Timeout sending command" [0] patch > reset the controller if it was busy for more than 500ms while your patch > doesn't. I don't mean that your patch is not correct, I'm just mentioning > because calling dw_mci_ctrl_reset() does makes the command to succeed the > next time and I can see the SDIO devices enumerated in /sys/bus/sdio/devices: > > [ 5.892124] dwmmc_exynos 12210000.mmc: Busy; trying anyway > [ 5.892135] mmc_host mmc2: Timeout sending command (cmd 0x202000 arg 0x0 status 0x0) > [ 5.913885] mmc2: new high speed SDIO card at address 0001 > [ 6.582133] dwmmc_exynos 12210000.mmc: Busy; trying anyway Hmmmmm. In the cases I was seeing I didn't need the "reset" since the "SDMMC_CMD_UPD_CLK" was the one from dw_mci_set_ios() and my patch: * mmc: dw_mmc: Give a good reset after we give power https://patchwork.kernel.org/patch/5858281/ ...gave the needed reset after vqmmc power was applied. Then dw_mmc never got wedged and didn't need the reset to get it unwedged. In your care you're getting called from dw_mci_init_card(). That should happen _after_ dw_mci_set_ios() as far as I know. Can you put a printout in the reset in dw_mci_set_ios() and make sure it runs? How many resets do you need before things work? If just one then something must be happening between the initial "set_ios" and the "init_card". Any chance you could figure out what that is? If it needs multiple resets then it seems like something is fishy... > but that reset may not be right since the WiFi chip does not work because > the firmware later fails to load: > > [ 240.273352] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > [ 240.281159] kworker/2:1 D c04b3340 0 1260 2 0x00000000 > [ 240.287487] Workqueue: events request_firmware_work_func > [ 240.292763] [<c04b3340>] (__schedule) from [<c04b36f0>] (schedule+0x34/0x98) > [ 240.299815] [<c04b36f0>] (schedule) from [<c04b7198>] (schedule_timeout+0x120/0x16c) > [ 240.307537] [<c04b7198>] (schedule_timeout) from [<c04b41b4>] (wait_for_common+0xb0/0x154) > [ 240.315783] [<c04b41b4>] (wait_for_common) from [<c037abb8>] (mmc_wait_for_req+0xa0/0x140) > [ 240.324020] [<c037abb8>] (mmc_wait_for_req) from [<c0384b04>] (mmc_io_rw_extended+0x304/0x34c) > [ 240.332607] [<c0384b04>] (mmc_io_rw_extended) from [<c0385a90>] (sdio_io_rw_ext_helper+0x138/0x1a4) > [ 240.341630] [<c0385a90>] (sdio_io_rw_ext_helper) from [<c0385b1c>] (sdio_writesb+0x20/0x28) > [ 240.349962] [<c0385b1c>] (sdio_writesb) from [<c02e60d4>] (mwifiex_write_data_sync+0x4c/0x80) > [ 240.358460] [<c02e60d4>] (mwifiex_write_data_sync) from [<c02e68e4>] (mwifiex_prog_fw_w_helper+0x1b0/0x2c4) > [ 240.368176] [<c02e68e4>] (mwifiex_prog_fw_w_helper) from [<c02c7d6c>] (mwifiex_dnld_fw+0x58/0x10c) > [ 240.377127] [<c02c7d6c>] (mwifiex_dnld_fw) from [<c02c5f10>] (mwifiex_fw_dpc+0x264/0x408) > [ 240.385263] [<c02c5f10>] (mwifiex_fw_dpc) from [<c0291b28>] (request_firmware_work_func+0x30/0x50) > [ 240.394200] [<c0291b28>] (request_firmware_work_func) from [<c0032ae8>] (process_one_work+0x120/0x324) > [ 240.403482] [<c0032ae8>] (process_one_work) from [<c0032e58>] (worker_thread+0x138/0x464) > [ 240.411635] [<c0032e58>] (worker_thread) from [<c0037470>] (kthread+0xd8/0xf4) > [ 240.418837] [<c0037470>] (kthread) from [<c000e680>] (ret_from_fork+0x14/0x34) > > The DTS changes on top of linux-next to add WiFi support is [1] in case you can > find something that is wrong with my patch. I still haven't had time to try using the new MMC power sequencing :( so I can't say for sure, but one thought below... > I also checked that the external reference clock for the WiFi module is enabled > correctly according to /sys/kernel/debug/clk/clk_summary and also by looking > at the value in the max77802 i2c register address that enables that clock. > > Any hints will be highly appreciated. > > Thanks a lot and best regards, > Javier > > [0]: https://lkml.org/lkml/2015/2/5/222 > [1]: > From ced0974472d109019e1ee551a6dd08f16ae5cfc2 Mon Sep 17 00:00:00 2001 > From: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx> > Date: Mon, 23 Feb 2014 15:42:15 +0100 > Subject: [PATCH] ARM: dts: Add Peach Pit board WiFi support > > Peach boards have an SDIO WiFi module that is always powered but it > needs a power sequence involving the reset and enable pins and also > a 32kHz reference clock. > > Add a dev node for the SDIO slot and the MMC power sequence provider. > > Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx> > --- > arch/arm/boot/dts/exynos5420-peach-pit.dts | 59 ++++++++++++++++++++++++++++++ > 1 file changed, 59 insertions(+) > > diff --git a/arch/arm/boot/dts/exynos5420-peach-pit.dts b/arch/arm/boot/dts/exynos5420-peach-pit.dts > index ec86d9523935..26df041e46e7 100644 > --- a/arch/arm/boot/dts/exynos5420-peach-pit.dts > +++ b/arch/arm/boot/dts/exynos5420-peach-pit.dts > @@ -125,6 +125,14 @@ > }; > }; > }; > + > + mmc1_pwrseq: mmc1_pwrseq { > + compatible = "mmc-pwrseq-simple"; > + reset-gpios = <&gpx0 1 GPIO_ACTIVE_LOW>, /* WIFI_RSTn */ > + <&gpx0 0 GPIO_ACTIVE_LOW>; /* WIFI_EN */ Any chance you want "WIFI_EN" to actually be specified as "vmmc" for the slot? ...possibly with a 'regulator-enable-ramp-delay' specified? I know that with SD Cards on an rk3288 board I needed to make sure there was a bit of delay after "vqmmc" came up... BTW: IIRC the "WIFI_RSTn" ended up being totally unused. It was used in earlier revs of the board that had a different rev of the WiFi chip... > + clocks = <&max77802 MAX77802_CLK_32K_CP>; > + clock-names = "ext_clock"; > + }; > }; > > &adc { > @@ -691,6 +699,24 @@ > bus-width = <8>; > }; > > +&mmc_1 { > + status = "okay"; > + num-slots = <1>; > + broken-cd; > + cap-sdio-irq; > + card-detect-delay = <200>; > + clock-frequency = <400000000>; > + samsung,dw-mshc-ciu-div = <1>; > + samsung,dw-mshc-sdr-timing = <0 1>; Just for kicks, does this help if you do: ciu-div = 3 sdr-timing = 2 3 ...I know we have ciu-div = 1 downstream, but we also have tuning... > + samsung,dw-mshc-ddr-timing = <0 2>; > + pinctrl-names = "default"; > + pinctrl-0 = <&sd1_clk>, <&sd1_cmd>, <&sd1_int>, <&sd1_bus4>, > + <&sd1_bus8>, <&wifi_en>, <&wifi_rst>; > + bus-width = <4>; > + cap-sd-highspeed; > + mmc-pwrseq = <&mmc1_pwrseq>; Should you be specifying a "vqmmc-supply" here? I know that we don't change voltages for WiFi (starts at 1.8V and ends up at 1.8V) but still might be good to specify it... > +}; > + > &mmc_2 { > status = "okay"; > num-slots = <1>; > @@ -710,6 +736,20 @@ > pinctrl-names = "default"; > pinctrl-0 = <&mask_tpm_reset>; > > + wifi_en: wifi-en { > + samsung,pins = "gpx0-0"; > + samsung,pin-function = <1>; > + samsung,pin-pud = <0>; > + samsung,pin-drv = <0>; > + }; > + > + wifi_rst: wifi-rst { > + samsung,pins = "gpx0-1"; > + samsung,pin-function = <1>; > + samsung,pin-pud = <0>; > + samsung,pin-drv = <0>; > + }; > + > max98090_irq: max98090-irq { > samsung,pins = "gpx0-2"; > samsung,pin-function = <0>; > @@ -797,6 +837,25 @@ > }; > }; > > +&pinctrl_1 { > + /* Adjust WiFi drive strengths lower for EMI */ > + sd1_clk: sd1-clk { > + samsung,pin-drv = <2>; > + }; > + > + sd1_cmd: sd1-cmd { > + samsung,pin-drv = <2>; > + }; > + > + sd1_bus4: sd1-bus-width4 { > + samsung,pin-drv = <2>; > + }; > + > + sd1_bus8: sd1-bus-width8 { > + samsung,pin-drv = <2>; > + }; > +}; > + > &pinctrl_2 { > pmic_dvs_2: pmic-dvs-2 { > samsung,pins = "gpj4-2"; > -- > 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
