Re: [PATCH 0/2] mmc: sdhci: add quirk to disable bounce buffer

[Michael Garofalo <officialtechflashyt@gmail.com>]

> On 08/10/2025 04:10, Michael Garofalo wrote:
>>> On 06/10/2025 12:28, Michael Garofalo wrote:
>>>>> On 06/10/2025 10:35, Adrian Hunter wrote:
>>>>>> On 06/10/2025 04:36, Michael Garofalo wrote:
>>>>>>> This patch series adds a new bit to quirks2 for disabling the bounce
>>>>>>> buffer.  On some hardware, this is required for proper operation.  An
>>>>>>> example of such hardware is the SDHCI controller of the Nintendo Wii's
>>>>>>> "Hollywood" chipset.  Without this patch, the onboard Broadcom 4318
>>>>>>> Wi-Fi fails to connect to any networks.
>>>>>>
>>>>>> The bounce buffer should not make any difference, so it is likely
>>>>>> a different problem that gets hidden when the bounce buffer is not
>>>>>> used.
>>>>>>
>>>>>>> Could you enable dynamic debug messages and show the messages
>>>>>>> for the failing case?
>>>>>>
>>>>>> Actually will also need to see the messages in the "fixed" case
>>>>>> to compare.
>>>> I'm afraid I won't be able to provide those easily, at least not with the
>>>> commands you've provided.  Since the rootfs is _also_ running from SD,
>>>> turning on full MMC logs like this produces an obscene amount of noise
>>>> from the storage, unrelated to the SDIO wireless.  It gets even worse with
>>>> my original intention, which was to save the logs to SD Card, (since my USB
>>>> Gecko serial console is rather flakey, and introduces corruption now and then),
>>>> since it's now logging the writes of it's own logs in a permanent loop.
>>>> If there's a way to narrow down the logs to specifically whatever portions
>>>> you're interested in, and filter out the noise, I would happily provide it.
>>>
>>> Are there any error messages?
>> If I drop the debug logs you mentioned so that I can actually see what's
>> going on (they produce hundreds of lines / sec), here's what the Wi-Fi card
>> actually reports with, vs without, MMC bounce buffers.  With bounce buffers on,
>> it takes several tries to load the firmware, and it can't authenticate to any
>> network.  I've tested and confirmed this effect on multiple consoles, across
>> multiple reboots, on multiple Wi-Fi networks.  Meanwhile with MMC bounce buffers
>> off, it's much more functional.
>> 
>> Logs with MMC bounce buffers *on* (without my patches):
>> [  168.492687] b43-sdio mmc1:0001:1: Chip ID 14e4:4318
>> [  168.493516] ssb: Found chip with id 0x4710, rev 0x00 an package 0x00
>> [  168.508519] ssb: WARNING: Multiple ChipCommon found
>> [  168.510597] b43-sdio mmc1:0001:1: Sonics Silicon Backplane found on SDIO device mmc1:0001:1
>> [  168.510886] b43-phy0: Broadcom 4710 WLAN found (core revision 9)
>> [  168.530151] b43-phy0: Found PHY: Analog 3, Type 2 (G), Revision 7
>> [  168.538447] b43-phy0: Found Radio: Manuf 0x17F, ID 0x2050, Revision 8, Version 0
>> [  168.719257] Broadcom 43xx driver loaded [ Features: S ]
>> [  168.722231] b43 ssb0:0: Direct firmware load for b43/ucode5.fw failed with error -2
>> [  168.724613] b43 ssb0:0: Direct firmware load for b43/ucode5.fw failed with error -2
>> [  168.740666] b43 ssb0:0: Direct firmware load for b43-open/pcm5.fw failed with error -2
>> [  168.762630] ieee80211 phy0: Slected rate control algorithm 'minstrel_ht'
>> [  176.156693] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  176.157159] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  179.993008] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  179.994373] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  186.940346] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  186.942559] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  216.368668] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  216.369135] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  221.750016] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  221.757700] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  223.437731] wlan0: authenticate with da:b3:70:18:7c:14 (local address=00:1c:be:ab:73:27)
>> [  223.437764] wlan0: send auth to da:b3:70:18:7c:14 (try 1/3)
>> [  223.648472] wlan0: send auth to da:b3:70:18:7c:14 (try 2/3)
>> [  223.859770] wlan0: send auth to da:b3:70:18:7c:14 (try 3/3)
>> [  224.064469] wlan0: authentication with da:b3:70:18:7c:14 timed out
>> [  226.045361] wlan0: authenticate with da:b3:70:18:7c:14 (local address=00:1c:be:ab:73:27)
>> [  226.045393] wlan0: send auth to da:b3:70:18:7c:14 (try 1/3)
>> [  226.248488] wlan0: send auth to da:b3:70:18:7c:14 (try 2/3)
>> [  226.462378] wlan0: send auth to da:b3:70:18:7c:14 (try 3/3)
>> [  226.664487] wlan0: authentication with da:b3:70:18:7c:14 timed out
>> [  250.424168] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  250.425629] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  255.806790] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  255.807256] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  257.467380] wlan0: authenticate with da:b3:70:18:7c:14 (local address=00:1c:be:ab:73:27)
>> [  257.467414] wlan0: send auth to da:b3:70:18:7c:14 (try 1/3)
>> [  257.672475] wlan0: send auth to da:b3:70:18:7c:14 (try 2/3)
>> [  257.880474] wlan0: send auth to da:b3:70:18:7c:14 (try 3/3)
>> [  258.093974] wlan0: authentication with da:b3:70:18:7c:14 timed out
>> [  284.326415] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  284.326922] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  289.836233] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  289.837612] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  291.528250] wlan0: authenticate with da:b3:70:18:7c:14 (local address=00:1c:be:ab:73:27)
>> [  291.528283] wlan0: send auth to da:b3:70:18:7c:14 (try 1/3)
>> [  291.736473] wlan0: send auth to da:b3:70:18:7c:14 (try 2/3)
>> [  291.944482] wlan0: send auth to da:b3:70:18:7c:14 (try 3/3)
>> [  292.152470] wlan0: authentication with da:b3:70:18:7c:14 timed out
>> <keeps trying and failing forever....>
>> 
>> Logs with MMC bounce buffers *off* (with my patches):
>> [  383.974268] b43-sdio mmc1:0001:1: Chip ID 14e4:4318
>> [  383.975824] ssb: Found chip with id 0x4710, rev 0x00 and package 0x00
>> [  383.986645] ssb: WARNING: Multiple ChipCommon found
>> [  383.987414] b43-sdio mmc1:0001:1: Sonics Silicon Backplane found on SDIO device mmc1:0001:1
>> [  383.987744] b43-phy0: Broadcom 4710 WLAN found (core revision 9)
>> [  383.995898] b43-phy0: Found PHY: Analog 3, Type 2 (G), Revision 7
>> [  383.996249] b43-phy0: Found Radio: Manuf 0x17F, ID 0x2050, Revision 8, Version 0
>> [  384.077562] b43 ssb0:0: Direct firmware load for b43/ucode5.fw failed with error -2
>> [  384.077687] b43 ssb0:0: Direct firmware load for b43/ucode5.fw failed with error -2
>> [  384.086571] Broadcom 43xx driver loaded [ Features: S ]
>> [  384.144620] b43 ssb0:0: Direct firmware load for b43-open/pcm5.fw failed with error -2
>> [  384.190831] ieee80211 phy0: Selected rate control algorithm 'minstrel_ht'
>> [  395.097838] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  395.098158] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  397.667851] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  397.668171] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  403.940787] b43-phy0: Loading OpenSource firmware version 410.31754
>> [  403.941110] b43-phy0: Hardware crypto acceleration not supported by firmware
>> [  405.366065] wlan0: authenticate with da:b3:70:18:7c:14 (local address=00:1c:be:ab:73:27)
>> [  405.366095] wlan0: send auth to da:b3:70:18:7c:14 (try 1/3)
>> [  405.389013] wlan0: authenticated
>> [  405.392814] wlan0: associate with da:b3:70:18:7c:14 (try 1/3)
>> [  405.600498] wlan0: associate with da:b3:70:18:7c:14 (try 2/3)
>> [  405.808479] wlan0: associate with da:b3:70:18:7c:14 (try 3/3)
>> [  406.016481] wlan0: association with da:b3:70:18:7c:14 timed out
>> [  414.301216] wlan0: authenticate with da:b3:70:18:7c:14 (local address=00:1c:be:ab:73:27)
>> [  414.301245] wlan0: send auth to da:b3:70:18:7c:14 (try 1/3)
>> [  414.351544] wlan0: authenticated
>> [  414.403769] wlan0: associate with da:b3:70:18:7c:14 (try 1/3)
>> [  414.422775] wlan0: RX AssocResp from da:b3:70:18:7c:14 (capab=0x1411 status=0 aid=25)
>> [  414.431879] wlan0: associated
>> [  415.272393] wlan0: Limiting TX power to 36 (36 - 0) dBm as advertised by da:b3:70:18:7c:14
>> 
>> If there's anything further that would be useful here, let me know and I'd be happy to provide them.
> 
> Seems the SDIO function driver b43-sdio does not print any error
> messages.  All the error paths in drivers/ssb/sdio.c print debug
> messages instead.
> 
> I would suggest the following, which would limit messages to
> host mmc1 which is what is shown in message "b43-sdio mmc1:0001:1:
> Chip ID 14e4:4318"
> 
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 860378bea557..2719b21783ad 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -169,33 +169,33 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
>  	 * - The card was removed (...so just complete everything no matter
>  	 *   if there are errors or retries)
>  	 */
> -	if (!err || !cmd->retries || mmc_card_removed(host->card)) {
> +	if (host->index == 1 && (!err || !cmd->retries || mmc_card_removed(host->card))) {
>  		mmc_should_fail_request(host, mrq);
>  
>  		if (!host->ongoing_mrq)
>  			led_trigger_event(host->led, LED_OFF);
>  
>  		if (mrq->sbc) {
> -			pr_debug("%s: req done <CMD%u>: %d: %08x %08x %08x %08x\n",
> +			pr_info("%s: req done <CMD%u>: %d: %08x %08x %08x %08x\n",
>  				mmc_hostname(host), mrq->sbc->opcode,
>  				mrq->sbc->error,
>  				mrq->sbc->resp[0], mrq->sbc->resp[1],
>  				mrq->sbc->resp[2], mrq->sbc->resp[3]);
>  		}
>  
> -		pr_debug("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n",
> +		pr_info("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n",
>  			mmc_hostname(host), cmd->opcode, err,
>  			cmd->resp[0], cmd->resp[1],
>  			cmd->resp[2], cmd->resp[3]);
>  
>  		if (mrq->data) {
> -			pr_debug("%s:     %d bytes transferred: %d\n",
> +			pr_info("%s:     %d bytes transferred: %d\n",
>  				mmc_hostname(host),
>  				mrq->data->bytes_xfered, mrq->data->error);
>  		}
>  
>  		if (mrq->stop) {
> -			pr_debug("%s:     (CMD%u): %d: %08x %08x %08x %08x\n",
> +			pr_info("%s:     (CMD%u): %d: %08x %08x %08x %08x\n",
>  				mmc_hostname(host), mrq->stop->opcode,
>  				mrq->stop->error,
>  				mrq->stop->resp[0], mrq->stop->resp[1],

With these patches, I still get copious amounts of spam, but at least relevant
to the wifi card now.
Here's a hopefully useful snippet (it's just a lot of these, from what I could see),
from with my patches:

[  154.177276] mmc1: req done (CMD53): 0: 00001000 00000000 00000000 00000000
[  154.177297] mmc1:     4 bytes transferred: 0
<...>
[  186.707195] mmc1: req done (CMD53): 0: 00001000 00000000 00000000 00000000
[  186.707217] mmc1:     20 bytes transferred: 0
[  186.707358] mmc1: req done (CMD53): 0: 00001000 00000000 00000000 00000000
[  186.707382] mmc1:     384 bytes transferred: 0
[  186.707477] mmc1: req done (CMD53): 0: 00001000 00000000 00000000 00000000
[  186.707498] mmc1:     24 bytes transferred: 0

And the one from without is very similar, except I noticed this pattern:
[   85.942269] mmc1: req done (CMD53): 0: 00001000 00000000 00000000 00000000
[   85.942299] mmc1:     4 bytes transferred: 0
[   85.942523] mmc1: req done (CMD53): 0: 00001000 00000000 00000000 00000000
[   85.942555] mmc1:     4 bytes transferred: 0
[   85.944548] mmc1: req done (CMD53): 0: 00001000 00000000 00000000 00000000
[   85.944581] mmc1:     2 bytes transferred: 0
[   85.944777] mmc1: req done (CMD53): 0: 00001000 00000000 00000000 00000000
[   85.945160] mmc1: req done (CMD53): 0: 00001000 00000000 00000000 00000000
[   85.945187] mmc1:     2 bytes transferred: 0
... occasionally, some of the requests don't have an "[x] bytes transferred: 0".

Hopefully these help.  I can get a capture of the entire log spam and
put it on on pastebin or something, if that would be more useful.