RE: mwifiex_sdio on chromebook

RE: mwifiex_sdio on chromebook

[Bing Zhao]

CC: linux-mmc

Hi Alexander,

> Hello.
> I am trying to debug the issue with incorrect initialization of WiFi chip on
> Samsung ARM Chromebook. And I search for assistance. I have posted my
> investigation results on launchpad.net (bug #1247512). Here is
> copy:
> 
> Marvell SDIO WiFi chip doesn't get initialized correctly on Chromebook.
> After some research I have managed to find that when Linux is doing
> initialization, it tries setting clock and power to SDIO controller for that chip. It
> is trying frequences hardcoded in
> linux/drivers/mmc/core/core.c: 400000, 300000, 200000, 100000 Hz.
> Opposed to that, chrome os kernel tries other frequences: 784314Hz and
> 50000000Hz. The last is staying as working frequency. I don't know, if it is
> matter for card what frequency does the host tries to gate.

Your Chromebook supports SDIO high speed mode (SDIO 2.0 spec). So 50MHz is correct.

> 
> When mainline kernel runs mmc_attach_sdio function it should get correct
> answer from card and so process card as SDIO. However it fails with timeout
> in that function.

What are you trying to do here? Are you trying to run a mainline kernel on your Chromebook?

> 
> I wonder if this depends on firmware loading. I see, that chrome os 3.4
> kernel requires firmware. And mainline is probably simply doesn't load it by
> default. Currently, I don't know how to check it and how to configure kernel
> to load firmware for mwifiex_sdio.

You said mmc_attach_sdio function fails. The mwifiex_sdio driver and the firmware will not be loaded at all.

> 
> I am ready to do further research, but I need some assistance.

CONFIG_MMC_DEBUG=y, and collect the debug logs.

Regards,
Bing

Re: mwifiex_sdio on chromebook

[Alexander Varnin]

[-- Attachment #1: Type: text/plain, Size: 1032 bytes --]

04.11.2013 02:10, Bing Zhao пишет:
> Your Chromebook supports SDIO high speed mode (SDIO 2.0 spec). So
> 50MHz is correct.

Ok, but mainline kernel doesn't try this frequency. It tries 400kHz at
most.

> What are you trying to do here? Are you trying to run a mainline kernel on your Chromebook?

Yes. I've got kernel 3.4 from Google Chrome OS. It works ok for
mwifiex_sdio. But I want to run mainline kernel. As of 3.11 it is able
to boot on Chromebook, but WiFi doesn't work.

> You said mmc_attach_sdio function fails. The mwifiex_sdio driver and
> the firmware will not be loaded at all. 

Ok, that is clear.

> CONFIG_MMC_DEBUG=y, and collect the debug logs.  

This way seems not very useful, because there is also internal and
external storage on mmc bus, so log quickly get garbaged with it. Dmesg
seems to be overflowed and forgets early initialization. I have made a
dirty hack to collect some useful info about initialization. I am
attaching it. Please check, if I need to add something. Will it be
useful this way?

[-- Attachment #2: dirty-hack.diff --]
[-- Type: text/x-patch, Size: 2948 bytes --]

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index bf18b6b..c4a2b22 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1001,12 +1001,16 @@ EXPORT_SYMBOL(mmc_put_card);
 static inline void mmc_set_ios(struct mmc_host *host)
 {
 	struct mmc_ios *ios = &host->ios;
-
-	pr_debug("%s: clock %uHz busmode %u powermode %u cs %u Vdd %u "
+	
+	if(((char*)mmc_hostname(host))[3]=='2') {
+	  printk("%s: clock %uHz busmode %u powermode %u cs %u Vdd %u "
 		"width %u timing %u\n",
 		 mmc_hostname(host), ios->clock, ios->bus_mode,
 		 ios->power_mode, ios->chip_select, ios->vdd,
 		 ios->bus_width, ios->timing);
+	
+	  dump_stack();
+	}
 
 	if (ios->clock > 0)
 		mmc_set_ungated(host);
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 80d89cff..0773be2 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -1133,11 +1133,14 @@ int mmc_attach_sdio(struct mmc_host *host)
 	int err, i, funcs;
 	u32 ocr;
 	struct mmc_card *card;
+	
+	printk("mmc_attach_sdio 1\n");
 
 	BUG_ON(!host);
 	WARN_ON(!host->claimed);
 
 	err = mmc_send_io_op_cond(host, 0, &ocr);
+	printk("mmc_attach_sdio err %d\n", err);
 	if (err)
 		return err;
 
@@ -1166,6 +1169,8 @@ int mmc_attach_sdio(struct mmc_host *host)
 		goto err;
 	}
 
+	printk("mmc_attach_sdio 2\n");
+	
 	/*
 	 * Detect and init the card.
 	 */
@@ -1182,11 +1187,13 @@ int mmc_attach_sdio(struct mmc_host *host)
 			host->ocr &= ~R4_18V_PRESENT;
 			err = mmc_sdio_init_card(host, host->ocr, NULL, 0);
 		}
+		printk("mmc_attach_sdio 3 err %d\n", err);
 		if (err)
 			goto err;
 	}
 	card = host->card;
 
+	printk("mmc_attach_sdio 4\n");
 	/*
 	 * Enable runtime PM only if supported by host+card+board
 	 */
@@ -1195,6 +1202,7 @@ int mmc_attach_sdio(struct mmc_host *host)
 		 * Let runtime PM core know our card is active
 		 */
 		err = pm_runtime_set_active(&card->dev);
+		printk("mmc_attach_sdio 5 err %d\n", err);
 		if (err)
 			goto remove;
 
@@ -1226,6 +1234,7 @@ int mmc_attach_sdio(struct mmc_host *host)
 			pm_runtime_enable(&card->sdio_func[i]->dev);
 	}
 
+	printk("mmc_attach_sdio 6\n");
 	/*
 	 * First add the card to the driver model...
 	 */
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 018f365..342b0c4 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1917,6 +1917,7 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
 
 	mmc->ops = &dw_mci_ops;
 	mmc->f_min = DIV_ROUND_UP(host->bus_hz, 510);
+	printk("f_min = %u;  %d", mmc->f_min, host->bus_hz);
 	mmc->f_max = host->bus_hz;
 
 	if (host->pdata->get_ocr)
diff --git a/drivers/net/wireless/mwifiex/Makefile b/drivers/net/wireless/mwifiex/Makefile
index a42a506..145f376 100644
--- a/drivers/net/wireless/mwifiex/Makefile
+++ b/drivers/net/wireless/mwifiex/Makefile
@@ -14,7 +14,10 @@
 # ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
 # this warranty disclaimer.
 

Re: mwifiex_sdio on chromebook

[Luis R. Rodriguez]

On Mon, Nov 4, 2013 at 3:18 AM, Alexander Varnin <fenixk19@mail.ru> wrote:
>> What are you trying to do here? Are you trying to run a mainline kernel on your Chromebook?
>
> Yes. I've got kernel 3.4 from Google Chrome OS. It works ok for
> mwifiex_sdio. But I want to run mainline kernel. As of 3.11 it is able
> to boot on Chromebook, but WiFi doesn't work.

WTF.

  Luis

RE: mwifiex_sdio on chromebook

[Bing Zhao]

Hi Alexander,

> > Your Chromebook supports SDIO high speed mode (SDIO 2.0 spec). So
> > 50MHz is correct.
> 
> Ok, but mainline kernel doesn't try this frequency. It tries 400kHz at
> most.
> 
> > What are you trying to do here? Are you trying to run a mainline kernel on your Chromebook?
> 
> Yes. I've got kernel 3.4 from Google Chrome OS. It works ok for
> mwifiex_sdio. But I want to run mainline kernel. As of 3.11 it is able
> to boot on Chromebook, but WiFi doesn't work.

I don't know why you want to do that, but the mainline kernel won't work on your Chromebook unless you port all platform specific changes over from chromeos-3.4 tree.

> 
> > You said mmc_attach_sdio function fails. The mwifiex_sdio driver and
> > the firmware will not be loaded at all.
> 
> Ok, that is clear.
> 
> > CONFIG_MMC_DEBUG=y, and collect the debug logs.
> 
> This way seems not very useful, because there is also internal and
> external storage on mmc bus, so log quickly get garbaged with it. Dmesg
> seems to be overflowed and forgets early initialization. I have made a
> dirty hack to collect some useful info about initialization. I am
> attaching it. Please check, if I need to add something. Will it be
> useful this way?

As said above, this won’t work because the Chromebook specific changes aren't present in mainline kernel. Anyway you can take a look at the chromium OS developer guide.

http://www.chromium.org/chromium-os/developer-guide

Thanks,
Bing

Re: mwifiex_sdio on chromebook

[Alexander Varnin]

04.11.2013 23:46, Bing Zhao пишет:
> Hi Alexander,
>
>>> Your Chromebook supports SDIO high speed mode (SDIO 2.0 spec). So
>>> 50MHz is correct.
>> Ok, but mainline kernel doesn't try this frequency. It tries 400kHz at
>> most.
>>
>>> What are you trying to do here? Are you trying to run a mainline kernel on your Chromebook?
>> Yes. I've got kernel 3.4 from Google Chrome OS. It works ok for
>> mwifiex_sdio. But I want to run mainline kernel. As of 3.11 it is able
>> to boot on Chromebook, but WiFi doesn't work.
> I don't know why you want to do that, but the mainline kernel won't work on your Chromebook unless you port all platform specific changes over from chromeos-3.4 tree.
>
>>> You said mmc_attach_sdio function fails. The mwifiex_sdio driver and
>>> the firmware will not be loaded at all.
>> Ok, that is clear.
>>
>>> CONFIG_MMC_DEBUG=y, and collect the debug logs.
>> This way seems not very useful, because there is also internal and
>> external storage on mmc bus, so log quickly get garbaged with it. Dmesg
>> seems to be overflowed and forgets early initialization. I have made a
>> dirty hack to collect some useful info about initialization. I am
>> attaching it. Please check, if I need to add something. Will it be
>> useful this way?
> As said above, this won’t work because the Chromebook specific changes aren't present in mainline kernel. Anyway you can take a look at the chromium OS developer guide.
>
> http://www.chromium.org/chromium-os/developer-guide
>
> Thanks,
> Bing
>

It is ported at most already and mainline kernel works good on
Chromebook. It is just peripheral problem.
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Re: mwifiex_sdio on chromebook

[Arend van Spriel]

On 11/05/2013 09:38 AM, Alexander Varnin wrote:
> 04.11.2013 23:46, Bing Zhao пишет:
>> Hi Alexander,
>>
>>>> Your Chromebook supports SDIO high speed mode (SDIO 2.0 spec). So
>>>> 50MHz is correct.
>>> Ok, but mainline kernel doesn't try this frequency. It tries 400kHz at
>>> most.
>>>
>>>> What are you trying to do here? Are you trying to run a mainline kernel on your Chromebook?
>>> Yes. I've got kernel 3.4 from Google Chrome OS. It works ok for
>>> mwifiex_sdio. But I want to run mainline kernel. As of 3.11 it is able
>>> to boot on Chromebook, but WiFi doesn't work.
>> I don't know why you want to do that, but the mainline kernel won't work on your Chromebook unless you port all platform specific changes over from chromeos-3.4 tree.
>>
>>>> You said mmc_attach_sdio function fails. The mwifiex_sdio driver and
>>>> the firmware will not be loaded at all.
>>> Ok, that is clear.
>>>
>>>> CONFIG_MMC_DEBUG=y, and collect the debug logs.
>>> This way seems not very useful, because there is also internal and
>>> external storage on mmc bus, so log quickly get garbaged with it. Dmesg
>>> seems to be overflowed and forgets early initialization. I have made a
>>> dirty hack to collect some useful info about initialization. I am
>>> attaching it. Please check, if I need to add something. Will it be
>>> useful this way?
>> As said above, this won’t work because the Chromebook specific changes aren't present in mainline kernel. Anyway you can take a look at the chromium OS developer guide.
>>
>> http://www.chromium.org/chromium-os/developer-guide
>>
>> Thanks,
>> Bing
>>
>
> It is ported at most already and mainline kernel works good on
> Chromebook. It is just peripheral problem.

Not sure how chromium os architecture looks like, but you mean to say 
*you* ported code in chromium user-space to work with upstream/mainline 
kernel API's?

Regards,
Arend

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Re: mwifiex_sdio on chromebook

[Alexander Varnin]

05.11.2013 12:53, Arend van Spriel пишет:
>>>
>>
>> It is ported at most already and mainline kernel works good on
>> Chromebook. It is just peripheral problem.
>
> Not sure how chromium os architecture looks like, but you mean to say
> *you* ported code in chromium user-space to work with
> upstream/mainline kernel API's? 

No. There is work doing by somebody from google or somewhere else, by
making mainline kernel work on Chromebook. Kernel 3.11 is the first
mainline kernel, that is able to boot and work on Chromebook. Working
parts is MMC controller, display controller, keyboard, etc. Not working
is usb, wifi, rtc, temperature sensors, etc.

By a tradition of open source, as I am interested, and I have experience
in kernel development, I have decided to debug wifi issue by myself. I
don't know, why I should port anything. Everything that was needed is
already ported - there is Chromebook device tree in kernel, there is all
required drivers. There is just a problem with powering up Marvell wifi
chip. I don't see, why fixing it requires any complex porting.

One thing worth doing is to compare 3.4 from chromeos and 3.4 mainline,
and find, if there any specific wifi changes. But there is possibly not.
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Re: mwifiex_sdio on chromebook

[Paul Stewart]

On Tue, Nov 5, 2013 at 1:12 AM, Alexander Varnin <fenixk19-JGs/UdohzUI@public.gmane.org> wrote:
> 05.11.2013 12:53, Arend van Spriel пишет:
>>>>
>>>
>>> It is ported at most already and mainline kernel works good on
>>> Chromebook. It is just peripheral problem.
>>
>> Not sure how chromium os architecture looks like, but you mean to say
>> *you* ported code in chromium user-space to work with
>> upstream/mainline kernel API's?
>
> No. There is work doing by somebody from google or somewhere else, by
> making mainline kernel work on Chromebook. Kernel 3.11 is the first
> mainline kernel, that is able to boot and work on Chromebook. Working
> parts is MMC controller, display controller, keyboard, etc. Not working
> is usb, wifi, rtc, temperature sensors, etc.

There doesn't appear a lot of effort into getting 3.11 working on the Samsung
ChromeBook yet.  There is some work on 3.8, which has more
architectural similarities to 3.11.  Offhand, the 3.4 version used a
"regulator" setup for controlling the GPIOs that performed power
sequencing and setup of the part, where as in 3.8 this work was moved
to the device tree.

Therefore, for more insights into the changes you may have to do for
3.11, I'd suggest that it'd be more informative for you to look at the
differences between mainline 3.8 and the "chromeos-3.8" branch of
https://chromium.googlesource.com/chromiumos/third_party/kernel-next

> By a tradition of open source, as I am interested, and I have experience
> in kernel development, I have decided to debug wifi issue by myself. I
> don't know, why I should port anything. Everything that was needed is
> already ported - there is Chromebook device tree in kernel, there is all
> required drivers. There is just a problem with powering up Marvell wifi
> chip. I don't see, why fixing it requires any complex porting.
>
> One thing worth doing is to compare 3.4 from chromeos and 3.4 mainline,
> and find, if there any specific wifi changes. But there is possibly not.
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