Re: [PATCH v3 0/5] Add support for SW babble Control
From: George Cherian
Date: Mon May 19 2014 - 04:40:29 EST
Hi Bin,
On 5/15/2014 8:49 PM, Bin Liu wrote:
George,
On Thu, May 15, 2014 at 1:28 AM, George Cherian <george.cherian@xxxxxx> wrote:
Hi Bin,
On 5/14/2014 10:13 PM, Bin Liu wrote:
George,
On Wed, May 14, 2014 at 9:34 AM, Bin Liu <binmlist@xxxxxxxxx> wrote:
George,
On Wed, May 14, 2014 at 12:37 AM, George Cherian <george.cherian@xxxxxx>
wrote:
On 5/14/2014 12:07 AM, Bin Liu wrote:
Hi,
On Tue, May 13, 2014 at 8:24 AM, George Cherian <george.cherian@xxxxxx>
wrote:
Hi Daniel,
On 5/13/2014 6:44 PM, Daniel Mack wrote:
Hi George,
On 05/13/2014 02:57 PM, George Cherian wrote:
I never enabled the MUSB_BABBLE_SW_SESSION_CTRL in the
MUSB_BABBLE_CTL
reg.
can you try with the following patch.
diff --git a/drivers/usb/musb/musb_dsps.c
b/drivers/usb/musb/musb_dsps.c
index 1ae6681..1160cd1 100644
--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -477,8 +477,11 @@ static int dsps_musb_init(struct musb *musb)
* logic enabled.
*/
val = dsps_readb(musb->mregs, MUSB_BABBLE_CTL);
- if (val == MUSB_BABBLE_RCV_DISABLE)
+ if (val == MUSB_BABBLE_RCV_DISABLE) {
glue->sw_babble_enabled = true;
+ val |= MUSB_BABBLE_SW_SESSION_CTRL;
+ dsps_writeb(musb->mregs, MUSB_BABBLE_CTL, val);
+ }
ret = dsps_musb_dbg_init(musb, glue);
if (ret)
MUSB_BABBLE_STUCK_J still remains unset, so I get the same result as
without the patch: a full glue reset is conducted. Do I get you right
that you expect MUSB_BABBLE_STUCK_J to be set in babble conditions
when
MUSB_BABBLE_SW_SESSION_CTRL is set?
Basically, there are 2 types of babble conditions.
1) Transient babble condition - which could be recovered from without
an
IP
reset .
2) Babble condition - which could be recovered from only by doing an
IP
reset.
Looks like you are always hitting case 2 (Most times am also hitting
the
same).
Case 1 is really hard to reproduce. I don't have a reliable method as
of
now
to
reproduce this case consistently.
[ 19.672373] CAUTION: musb: Babble Interrupt Occurred
[ 19.677776] musb_stage0_irq 789: unhandled DISCONNECT transition
(a_wait_bcon)
[ 19.685815] usb 1-1: USB disconnect, device number 3
[ 19.769720] musb-hdrc musb-hdrc.0.auto: babble: MUSB_BABBLE_CTL
value
44
[ 19.776765] musb-hdrc musb-hdrc.0.auto: STUCK_J is reset
I don't quite follow, especially as I lack documentation of the IP
core.
How do you test babble errors, is there any way to force them to
happen
reliably?
There is no 100% reliable method to force it to happen. Following is
I have a way to force babble happen reliably - shorting DP or DM to
VBUS. I opened the far-end plug of the USB cable, so I can easily
short DP or DM to VBUS.
Good to know that you have a reliable way to test babble condition.
Can you please do a quick test on 3.15.0-rc4 with the series applied?
In case of any assistance please do let me know.
Sure, but could you please re-send those patches to my corporate email
so that I can apply them from Thunderbird?
You don't have to resend the patches. Nishanth Menon showed me a way
to extract the patch from Gmail - Thanks Nishanth.
But which repo do you want to me test with? The first patch ([PATCH v2
1/5] usb: musb: core: Convert babble recover work to delayed work)
does not apply to v3.15-rc4 tag. the current musb_core.c does not have
the recovery work for musb. Please let me know what I missed.
Oops I missed to mention the same.
Please try on
git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git master
The test is done. The babble always causes STUCK_J is reset,
MUSB_BABBLE_CTL is 0x44 or 0x4. MUSB reset happens.
Thankyou Bin for the help.
Can I get a Tested-by from you?
Do you think when re-start happens the driver should print a message
on console saying re-start due to babble? It would help debug the
babble problems while the dynamic debug is off.
It prints out a message saying babble condition occured.
More over, it re-enumerates all the devices connected as part of Musb
re-start.
Don't you think that is sufficient enough ?
Thanks,
-Bin.
Thanks,
-Bin.
I read these linux-usb emails in Gmail, and am not aware of any easy
way to extract patches from Gmail.
BTY, I tested with TI 3.12.10 kernel, in which I guess the babble
handling is similar to this patch set. With TI3.12.10, MISC is always
0x64, so MUSB never restarts.
Thanks,
-Bin.
But the interesting thing is that with TI 3.2 kernel, shorting DP or
DM to VBUS causes MISC register to be 0x4, but the result is
completely opposite in TI 3.12.10 kernel, which cause MISC to be 0x64.
So in the 3.2 kernel, the babble handing resets the controller, but
the 3.12.10 does not.
Regards,
-Bin.
my setup ,
I have a HUB with 4 devices connected , which gives me a Babble
interrupt
on both connects and disconnects ( Not always though).
Anyway, the full glue layer solves this rare condition quite well for
me. Is there any downside of this?
Daniel
--
-George
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-George
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-George
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-George
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