mvebu: usb: Add missing controller reset after initialization

PATCH New Phil Sutter 4 participants 9 messages Jan 2, 2016 – Mar 24, 2016

Subsystems (3)

Arm (32-bit) Arm sub-architectures Arm/Marvell Kirkwood and Armada 370, 375, 38x, 39x, XP, 3700, 7K/8K, CN9130 SoC support

lore

Share & tools

lore

Phil Sutter

author

2016-01-02 21:19 UTC #0 lore raw

PATCH 1/1 mvebu: usb: Add missing controller reset after initialization

In order to allow for Linux properly register the integrated EHCI host, we have to reset it after initialization. Without this, enumeration fails if 'usb start' wasn't issued prior to booting Linux.

Signed-off-by Phil Sutter <[email protected]>

---
 arch/arm/mach-mvebu/cpu.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

arch/arm/mach-mvebu/cpu.c +12 -0

index 5c62fd5..cb885f8 100644
@@ -281,6 +281,8 @@ static void set_cbar(u32 addr)
 					 (((addr) & 0xF) << 6))
 #define MV_USB_X3_PHY_CHANNEL(dev, reg)	(MV_USB_X3_BASE((dev) + 1) |	\
 					 (((reg) & 0xF) << 2))
+#define MV_USB_CMD_REG(dev)		(MVEBU_AXP_USB_BASE + (dev * 0x1000) + 0x140)
+#define MV_USB_MODE_REG(dev)		(MVEBU_AXP_USB_BASE + (dev * 0x1000) + 0x1A8)
 
 static void setup_usb_phys(void)
 {

@@ -313,6 +315,16 @@ static void setup_usb_phys(void)
 		setbits_le32(MV_USB_X3_PHY_CHANNEL(dev, 1), BIT(12));
 		udelay(40);
 		clrbits_le32(MV_USB_X3_PHY_CHANNEL(dev, 1), BIT(12));
+
+		/* disable (bit 0) and reset (bit 1) controller */
+		/* XXX: do this in two steps? */
+		clrsetbits_le32(MV_USB_CMD_REG(dev), BIT(0), BIT(1));
+
+		while(readl(MV_USB_CMD_REG(dev)) & BIT(1))
+			;
+
+		/* set host mode (device mode is (0x2 | 1 << 3)) */
+		writel(0x3, MV_USB_MODE_REG(dev));
 	}
 }

Signature · 1 line

2.5.3

Wolfgang Denk

2016-01-03 08:59 UTC #1 lore raw

PATCH 1/1 mvebu: usb: Add missing controller reset after initialization

Dear Phil,

[added USB custodian to Cc:]

Quoted 3 lines · In message <[email protected]> you wrote:

In order to allow for Linux properly register the integrated EHCI host, we have to reset it after initialization. Without this, enumeration fails if 'usb start' wasn't issued prior to booting Linux.

I think this reset should actually be done in the Linux driver.

From what you write I suspect that after a "usb stop" in U-Boot the Linux driver maight fail, too. Leaving USB enabled in U-Boot is extremely dangerous - see

commit 3d71c81a9bb03f866a1e98da96363ef3f46c76b3

Author: Markus Klotzb?cher <[email protected]>
Date:   Thu Jul 10 14:47:09 2008 +0200

USB: shutdown USB before booting

This patch fixes a potentially serious issue related to USB which was discouvered by Martin Krause <[email protected]> and fixed for ARM920T. Martin wrote:

Turn off USB to prevent the host controller from writing to the SDRAM while Linux is booting. This could happen, because the HCCA (Host Controller Communication Area) lies within the SDRAM and the host controller writes continously to this area (as busmaster!), for example to increase the HccaFrameNumber variable, which happens every 1 ms.

This is a slightly modified version of the patch in order to shutdown USB when booting on all architectures.

Signed-off-by Markus Klotzbuecher <[email protected]>

Best regards,

Wolfgang Denk

Signature · 5 lines

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
A wise person makes his  own  decisions,  a  weak  one  obeys  public
opinion.                                           -- Chinese proverb

Marek Vasut

2016-01-03 09:35 UTC #2 lore raw

PATCH 1/1 mvebu: usb: Add missing controller reset after initialization

Quoted 3 lines · Wolfgang Denk

Dear Phil,
[added USB custodian to Cc:]

Thanks

Quoted 6 lines

Quoted 3 lines · In message <[email protected]> you wrote:
In order to allow for Linux properly register the integrated EHCI host, we have to reset it after initialization. Without this, enumeration fails if 'usb start' wasn't issued prior to booting Linux.
I think this reset should actually be done in the Linux driver.

Correct.

Quoted 21 lines

From what you write I suspect that after a "usb stop" in U-Boot the Linux driver maight fail, too. Leaving USB enabled in U-Boot is extremely dangerous - see
commit 3d71c81a9bb03f866a1e98da96363ef3f46c76b3
Author: Markus Klotzb?cher <[email protected]>
Date:   Thu Jul 10 14:47:09 2008 +0200
USB: shutdown USB before booting
This patch fixes a potentially serious issue related to USB which was discouvered by Martin Krause <[email protected]> and fixed for ARM920T. Martin wrote:
Turn off USB to prevent the host controller from writing to the SDRAM while Linux is booting. This could happen, because the HCCA (Host Controller Communication Area) lies within the SDRAM and the host controller writes continously to this area (as busmaster!), for example to increase the HccaFrameNumber variable, which happens every 1 ms.

Quoted 4 lines

This is a slightly modified version of the patch in order to shutdown USB when booting on all architectures.
Signed-off-by Markus Klotzbuecher <[email protected]>

This reasoning is correct.

Best regards,
Marek Vasut

Phil Sutter

author

2016-01-03 23:38 UTC #3 lore raw

PATCH 1/1 mvebu: usb: Add missing controller reset after initialization

In reply to Wolfgang Denk

Hi,

Quoted 7 lines · Wolfgang Denk

[added USB custodian to Cc:]
Quoted 3 lines · In message <[email protected]> you wrote:
In order to allow for Linux properly register the integrated EHCI host, we have to reset it after initialization. Without this, enumeration fails if 'usb start' wasn't issued prior to booting Linux.

Quoted 5 lines

I think this reset should actually be done in the Linux driver.
From what you write I suspect that after a "usb stop" in U-Boot the Linux driver maight fail, too. Leaving USB enabled in U-Boot is extremely dangerous - see

Ah, thanks for pointing this out! I had no idea the HCD does things like this. Though I'm a bit confused now how to solve the issue at hand:

Quoted 17 lines

commit 3d71c81a9bb03f866a1e98da96363ef3f46c76b3
Author: Markus Klotzb?cher <[email protected]>
Date:   Thu Jul 10 14:47:09 2008 +0200
USB: shutdown USB before booting
This patch fixes a potentially serious issue related to USB which was discouvered by Martin Krause <[email protected]> and fixed for ARM920T. Martin wrote:
Turn off USB to prevent the host controller from writing to the SDRAM while Linux is booting. This could happen, because the HCCA (Host Controller Communication Area) lies within the SDRAM and the host controller writes continously to this area (as busmaster!), for example to increase the HccaFrameNumber variable, which happens every 1 ms.

Quoted 4 lines

This is a slightly modified version of the patch in order to shutdown USB when booting on all architectures.
Signed-off-by Markus Klotzbuecher <[email protected]>

This commit exists in my tree, therefore when I call 'bootm' it should stop USB. To be sure, I tested calling 'usb stop' manually before doing 'tftpboot; bootm' and the enumeration still succeeds in Linux.

Since this all does not seem to make much sense, I reviewed my changes again to see if the controller really is enabled after the reset - it is not, but I found something more important: The reset is actually not necessary at all!

The bit which really was missing is the USB mode setting I smuggled in along with my patch - setting the devices to host mode is sufficient for Linux to successfully enumerate the HCD.

Checking the logs of the vendor's U-Boot fork, it appears that devices 1 and 2 are configured to host mode, while the third is set to device mode. I changed my code to copy that, but am not sure it's necessary at
all: The DS414 exports only a single port of the SoC's EHCI, and Linux detects that:

| orion-ehci f1050000.usb: EHCI Host Controller
| orion-ehci f1050000.usb: new USB bus registered, assigned bus number 3
| orion-ehci f1050000.usb: irq 27, io mem 0xf1050000
| orion-ehci f1050000.usb: USB 2.0 started, EHCI 1.00
| hub 3-0:1.0: USB hub found
| hub 3-0:1.0: 1 port detected

OTOH I'm not sure how far this configuration is device specific in the first place. What puzzles me is that I couldn't find a reference to this USB mode register at 0x501A8 in Marvell's MV78230 specs, still it seems to be crucial. Does anyone of you have this register referenced in some Marvell datasheet somewhere?

Maybe there's also a more generic way to do this, 'usb start' (which solves the problem without any changes to the SoC init code) seems to not address this register.

Thanks, Phil

Marek Vasut

2016-01-03 23:47 UTC #4 lore raw

PATCH 1/1 mvebu: usb: Add missing controller reset after initialization

Quoted 45 lines · Phil Sutter

Hi,
Quoted 7 lines · Wolfgang Denk
[added USB custodian to Cc:]
Quoted 3 lines · In message <[email protected]> you wrote:
In order to allow for Linux properly register the integrated EHCI host, we have to reset it after initialization. Without this, enumeration fails if 'usb start' wasn't issued prior to booting Linux.
Quoted 5 lines
I think this reset should actually be done in the Linux driver.
From what you write I suspect that after a "usb stop" in U-Boot the Linux driver maight fail, too. Leaving USB enabled in U-Boot is extremely dangerous - see
Ah, thanks for pointing this out! I had no idea the HCD does things like
this. Though I'm a bit confused now how to solve the issue at hand:
Quoted 17 lines
commit 3d71c81a9bb03f866a1e98da96363ef3f46c76b3
Author: Markus Klotzb?cher <[email protected]>
Date:   Thu Jul 10 14:47:09 2008 +0200
USB: shutdown USB before booting
This patch fixes a potentially serious issue related to USB which was discouvered by Martin Krause <[email protected]> and fixed for
ARM920T. Martin wrote:
Turn off USB to prevent the host controller from writing to the SDRAM while Linux is booting. This could happen, because the HCCA (Host Controller Communication Area) lies within the SDRAM and the host controller writes continously to this area (as busmaster!), for example to increase the HccaFrameNumber variable, which happens every 1 ms.
Quoted 4 lines
This is a slightly modified version of the patch in order to shutdown USB when booting on all architectures.
Signed-off-by Markus Klotzbuecher <[email protected]>
This commit exists in my tree, therefore when I call 'bootm' it should stop USB. To be sure, I tested calling 'usb stop' manually before doing 'tftpboot; bootm' and the enumeration still succeeds in Linux.

Quoted 8 lines

Since this all does not seem to make much sense, I reviewed my changes again to see if the controller really is enabled after the reset - it is not, but I found something more important: The reset is actually not necessary at all!
The bit which really was missing is the USB mode setting I smuggled in along with my patch - setting the devices to host mode is sufficient for Linux to successfully enumerate the HCD.

OK, so the controller is OTG capable and upon reset, it's in Gadget mode?

Quoted 13 lines

Checking the logs of the vendor's U-Boot fork, it appears that devices 1 and 2 are configured to host mode, while the third is set to device mode. I changed my code to copy that, but am not sure it's necessary at
all: The DS414 exports only a single port of the SoC's EHCI, and Linux
detects that:
| orion-ehci f1050000.usb: EHCI Host Controller
| orion-ehci f1050000.usb: new USB bus registered, assigned bus number 3
| orion-ehci f1050000.usb: irq 27, io mem 0xf1050000
| orion-ehci f1050000.usb: USB 2.0 started, EHCI 1.00
| hub 3-0:1.0: USB hub found
| hub 3-0:1.0: 1 port detected

Quoted 5 lines

OTOH I'm not sure how far this configuration is device specific in the first place. What puzzles me is that I couldn't find a reference to this USB mode register at 0x501A8 in Marvell's MV78230 specs, still it seems to be crucial. Does anyone of you have this register referenced in some Marvell datasheet somewhere?

It's the USBMODE register, see for example [1] . It's part of EHCI cores which are OTG capable.

[1] http://lxr.free-electrons.com/source/drivers/usb/host/ehci-hcd.c#L179

Quoted 3 lines

Maybe there's also a more generic way to do this, 'usb start' (which solves the problem without any changes to the SoC init code) seems to not address this register.

Probably add a fixup into ehci-orion.c in Linux or something along those lines. It should configure the code according to the "dr_mode" DT prop.

Phil Sutter

author

2016-01-04 03:02 UTC #5 lore raw

PATCH 1/1 mvebu: usb: Add missing controller reset after initialization

Hi,

Quoted 6 lines · Marek Vasut

Quoted 3 lines · Phil Sutter
The bit which really was missing is the USB mode setting I smuggled in along with my patch - setting the devices to host mode is sufficient for Linux to successfully enumerate the HCD.
OK, so the controller is OTG capable and upon reset, it's in Gadget mode?

Yes, seems it's capable. Upon reset, register 0x501a0 contains value 0. Trying to print register 0x511a0 freezes U-Boot for me.

Quoted 19 lines

Quoted 13 lines
Checking the logs of the vendor's U-Boot fork, it appears that devices 1 and 2 are configured to host mode, while the third is set to device mode. I changed my code to copy that, but am not sure it's necessary at
all: The DS414 exports only a single port of the SoC's EHCI, and Linux
detects that:
| orion-ehci f1050000.usb: EHCI Host Controller
| orion-ehci f1050000.usb: new USB bus registered, assigned bus number 3
| orion-ehci f1050000.usb: irq 27, io mem 0xf1050000
| orion-ehci f1050000.usb: USB 2.0 started, EHCI 1.00
| hub 3-0:1.0: USB hub found
| hub 3-0:1.0: 1 port detected
Quoted 5 lines
OTOH I'm not sure how far this configuration is device specific in the first place. What puzzles me is that I couldn't find a reference to this USB mode register at 0x501A8 in Marvell's MV78230 specs, still it seems to be crucial. Does anyone of you have this register referenced in some Marvell datasheet somewhere?

Quoted 4 lines

It's the USBMODE register, see for example [1] . It's part of EHCI cores which are OTG capable.
[1] http://lxr.free-electrons.com/source/drivers/usb/host/ehci-hcd.c#L179

Interesting. I would have expected this to show up in MV78230 specs, but maybe I missed the part where it clarifies these offsets to be standard conformant.

Quoted 6 lines

Quoted 3 lines
Maybe there's also a more generic way to do this, 'usb start' (which solves the problem without any changes to the SoC init code) seems to not address this register.
Probably add a fixup into ehci-orion.c in Linux or something along those lines. It should configure the code according to the "dr_mode" DT prop.

Hmm. Searching through the relevant DT files didn't yield a result for "dr_mode". Seems like this property is missing, maybe that's why Linux fails here? Is this something generally user-configurable? (Note that I don't have the slightest idea of how device mode USB works in Linux).

Thanks, Phil

Marek Vasut

2016-01-04 11:25 UTC #6 lore raw

PATCH 1/1 mvebu: usb: Add missing controller reset after initialization

Quoted 4 lines · Phil Sutter

Hi,
Quoted 1 line · Marek Vasut
On Monday, January 04, 2016 at 12:38:07 AM, Phil Sutter wrote:

Quoted 8 lines

Quoted 5 lines
Quoted 3 lines
The bit which really was missing is the USB mode setting I smuggled in along with my patch - setting the devices to host mode is sufficient for Linux to successfully enumerate the HCD.
OK, so the controller is OTG capable and upon reset, it's in Gadget mode?
Yes, seems it's capable. Upon reset, register 0x501a0 contains value 0. Trying to print register 0x511a0 freezes U-Boot for me.

0x501a0 and 0x511a0 are two different registers. Freeze usually indicates disabled clock to the IP block or somesuch.

Quoted 20 lines

Quoted 20 lines
Quoted 19 lines
Checking the logs of the vendor's U-Boot fork, it appears that devices 1 and 2 are configured to host mode, while the third is set to device mode. I changed my code to copy that, but am not sure it's necessary at all: The DS414 exports only a single port of the SoC's EHCI, and Linux
detects that:
| orion-ehci f1050000.usb: EHCI Host Controller
| orion-ehci f1050000.usb: new USB bus registered, assigned bus number
| 3 orion-ehci f1050000.usb: irq 27, io mem 0xf1050000
| orion-ehci f1050000.usb: USB 2.0 started, EHCI 1.00
| hub 3-0:1.0: USB hub found
| hub 3-0:1.0: 1 port detected
OTOH I'm not sure how far this configuration is device specific in the first place. What puzzles me is that I couldn't find a reference to this USB mode register at 0x501A8 in Marvell's MV78230 specs, still it seems to be crucial. Does anyone of you have this register referenced in some Marvell datasheet somewhere?

Quoted 8 lines

Quoted 4 lines
It's the USBMODE register, see for example [1] . It's part of EHCI cores which are OTG capable.
[1] http://lxr.free-electrons.com/source/drivers/usb/host/ehci-hcd.c#L179
Interesting. I would have expected this to show up in MV78230 specs, but maybe I missed the part where it clarifies these offsets to be standard conformant.

It seems to be standard comformant, but I didn't see the datasheet.

Quoted 10 lines

Quoted 6 lines
Quoted 3 lines
Maybe there's also a more generic way to do this, 'usb start' (which solves the problem without any changes to the SoC init code) seems to not address this register.
Probably add a fixup into ehci-orion.c in Linux or something along those lines. It should configure the code according to the "dr_mode" DT prop.
Hmm. Searching through the relevant DT files didn't yield a result for "dr_mode". Seems like this property is missing, maybe that's why Linux fails here?

More likely it's not implemented for the MVEBU yet.

Quoted 2 lines

Is this something generally user-configurable? (Note that I don't have the slightest idea of how device mode USB works in Linux).

Yes, you can run the core in either Host/Gadget/OTG mode. For that to work, you need to configure the core mode.

Best regards,
Marek Vasut

Stefan Roese

2016-03-24 09:13 UTC #7 lore raw

PATCH 1/1 mvebu: usb: Add missing controller reset after initialization

Quoted 59 lines · Marek Vasut

Quoted 4 lines · Phil Sutter
Hi,
Quoted 1 line · Marek Vasut
On Monday, January 04, 2016 at 12:38:07 AM, Phil Sutter wrote:
Quoted 8 lines
Quoted 5 lines
Quoted 3 lines
The bit which really was missing is the USB mode setting I smuggled in along with my patch - setting the devices to host mode is sufficient for Linux to successfully enumerate the HCD.
OK, so the controller is OTG capable and upon reset, it's in Gadget mode?
Yes, seems it's capable. Upon reset, register 0x501a0 contains value 0. Trying to print register 0x511a0 freezes U-Boot for me.
0x501a0 and 0x511a0 are two different registers. Freeze usually indicates disabled clock to the IP block or somesuch.
Quoted 20 lines
Quoted 20 lines
Quoted 19 lines
Checking the logs of the vendor's U-Boot fork, it appears that devices 1 and 2 are configured to host mode, while the third is set to device mode. I changed my code to copy that, but am not sure it's necessary at all: The DS414 exports only a single port of the SoC's EHCI, and Linux
detects that:
| orion-ehci f1050000.usb: EHCI Host Controller
| orion-ehci f1050000.usb: new USB bus registered, assigned bus number
| 3 orion-ehci f1050000.usb: irq 27, io mem 0xf1050000
| orion-ehci f1050000.usb: USB 2.0 started, EHCI 1.00
| hub 3-0:1.0: USB hub found
| hub 3-0:1.0: 1 port detected
OTOH I'm not sure how far this configuration is device specific in the first place. What puzzles me is that I couldn't find a reference to this USB mode register at 0x501A8 in Marvell's MV78230 specs, still it seems to be crucial. Does anyone of you have this register referenced in some Marvell datasheet somewhere?
Quoted 8 lines
Quoted 4 lines
It's the USBMODE register, see for example [1] . It's part of EHCI cores which are OTG capable.
[1] http://lxr.free-electrons.com/source/drivers/usb/host/ehci-hcd.c#L179
Interesting. I would have expected this to show up in MV78230 specs, but maybe I missed the part where it clarifies these offsets to be standard conformant.
It seems to be standard comformant, but I didn't see the datasheet.
Quoted 10 lines
Quoted 6 lines
Quoted 3 lines
Maybe there's also a more generic way to do this, 'usb start' (which solves the problem without any changes to the SoC init code) seems to not address this register.
Probably add a fixup into ehci-orion.c in Linux or something along those lines. It should configure the code according to the "dr_mode" DT prop.
Hmm. Searching through the relevant DT files didn't yield a result for "dr_mode". Seems like this property is missing, maybe that's why Linux fails here?

Quoted 7 lines

More likely it's not implemented for the MVEBU yet.
Quoted 2 lines
Is this something generally user-configurable? (Note that I don't have the slightest idea of how device mode USB works in Linux).
Yes, you can run the core in either Host/Gadget/OTG mode. For that to work, you need to configure the core mode.

I've not followed the discussion and just now going through my list of open patches.

Phil, what is the current status of this patch? Is it still needed?

Thanks,
Stefan

Phil Sutter

author

2016-03-24 09:47 UTC #8 lore raw

PATCH 1/1 mvebu: usb: Add missing controller reset after initialization

Quoted 65 lines · Stefan Roese

Quoted 64 lines · Marek Vasut
Quoted 4 lines · Phil Sutter
Hi,
Quoted 1 line · Marek Vasut
On Monday, January 04, 2016 at 12:38:07 AM, Phil Sutter wrote:
Quoted 8 lines
Quoted 5 lines
Quoted 3 lines
The bit which really was missing is the USB mode setting I smuggled in along with my patch - setting the devices to host mode is sufficient for Linux to successfully enumerate the HCD.
OK, so the controller is OTG capable and upon reset, it's in Gadget mode?
Yes, seems it's capable. Upon reset, register 0x501a0 contains value 0. Trying to print register 0x511a0 freezes U-Boot for me.
0x501a0 and 0x511a0 are two different registers. Freeze usually indicates disabled clock to the IP block or somesuch.
Quoted 20 lines
Quoted 20 lines
Quoted 19 lines
Checking the logs of the vendor's U-Boot fork, it appears that devices 1 and 2 are configured to host mode, while the third is set to device mode. I changed my code to copy that, but am not sure it's necessary at all: The DS414 exports only a single port of the SoC's EHCI, and Linux
detects that:
| orion-ehci f1050000.usb: EHCI Host Controller
| orion-ehci f1050000.usb: new USB bus registered, assigned bus number
| 3 orion-ehci f1050000.usb: irq 27, io mem 0xf1050000
| orion-ehci f1050000.usb: USB 2.0 started, EHCI 1.00
| hub 3-0:1.0: USB hub found
| hub 3-0:1.0: 1 port detected
OTOH I'm not sure how far this configuration is device specific in the first place. What puzzles me is that I couldn't find a reference to this USB mode register at 0x501A8 in Marvell's MV78230 specs, still it seems to be crucial. Does anyone of you have this register referenced in some Marvell datasheet somewhere?
Quoted 8 lines
Quoted 4 lines
It's the USBMODE register, see for example [1] . It's part of EHCI cores which are OTG capable.
[1] http://lxr.free-electrons.com/source/drivers/usb/host/ehci-hcd.c#L179
Interesting. I would have expected this to show up in MV78230 specs, but maybe I missed the part where it clarifies these offsets to be standard conformant.
It seems to be standard comformant, but I didn't see the datasheet.
Quoted 10 lines
Quoted 6 lines
Quoted 3 lines
Maybe there's also a more generic way to do this, 'usb start' (which solves the problem without any changes to the SoC init code) seems to not address this register.
Probably add a fixup into ehci-orion.c in Linux or something along those lines. It should configure the code according to the "dr_mode" DT prop.
Hmm. Searching through the relevant DT files didn't yield a result for "dr_mode". Seems like this property is missing, maybe that's why Linux fails here?
More likely it's not implemented for the MVEBU yet.
Quoted 2 lines
Is this something generally user-configurable? (Note that I don't have the slightest idea of how device mode USB works in Linux).

Quoted 7 lines

Quoted 2 lines
Yes, you can run the core in either Host/Gadget/OTG mode. For that to work, you need to configure the core mode.
I've not followed the discussion and just now going through my list of open patches.
Phil, what is the current status of this patch? Is it still needed?

I reported the issue to linux-usb list back in January, but never got any usable reply. So no progress upstream.

Also, it seems that even with this patch the front USB port is not usable in Linux, no devices are detected.

Cheers, Phil