diff mbox

[v7,3/5] usb: dwc3: omap: Don't set POWERPRESENT

Message ID 1462873919-20532-4-git-send-email-rogerq@ti.com
State Superseded
Headers show

Commit Message

Roger Quadros May 10, 2016, 9:51 a.m. UTC
TRM [1] recommends that POWERPRESENT bit must not be
set and left at it's default value of 0.

[1] OMAP542x TRM - http://www.ti.com/lit/pdf/swpu249
Section 23.11.4.5.1 Mailbox VBUS/ID Management

"Because PIPE powerpresent has a different meaning in host and in device mode,
and because of the redundancy with the UTMI signals, the controller ORes
together the appropriate PIPE and UTMI inputs to create its internal
VBUS status. For that reason, it is recommended to leave field
USBOTGSS_UTMI_OTG_STATUS[9] POWERPRESENT at its default value (=0), and only to
fill in the USB2 VBUS status fields in the same register."

Signed-off-by: Roger Quadros <rogerq@ti.com>

---
 drivers/usb/dwc3/dwc3-omap.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

-- 
2.7.4

Comments

Roger Quadros May 10, 2016, 9:59 a.m. UTC | #1
On 10/05/16 12:54, Felipe Balbi wrote:
> 

> Hi,

> 

> Roger Quadros <rogerq@ti.com> writes:

>> TRM [1] recommends that POWERPRESENT bit must not be

>> set and left at it's default value of 0.

>>

>> [1] OMAP542x TRM - http://www.ti.com/lit/pdf/swpu249

>> Section 23.11.4.5.1 Mailbox VBUS/ID Management

>>

>> "Because PIPE powerpresent has a different meaning in host and in device mode,

>> and because of the redundancy with the UTMI signals, the controller ORes

>> together the appropriate PIPE and UTMI inputs to create its internal

>> VBUS status. For that reason, it is recommended to leave field

>> USBOTGSS_UTMI_OTG_STATUS[9] POWERPRESENT at its default value (=0), and only to

>> fill in the USB2 VBUS status fields in the same register."

>>

>> Signed-off-by: Roger Quadros <rogerq@ti.com>

> 

> to make sure we avoid regressions, do you mind sharing on which

> platforms you tested this patch ?

> 

I tested this on omap5-uevm and dra7-evm.
My am437x board stopped working so couldn't test on that one.

cheers,
-roger
Roger Quadros May 10, 2016, 10:23 a.m. UTC | #2
On 10/05/16 13:04, Felipe Balbi wrote:
> 

> Hi,

> 

> Roger Quadros <rogerq@ti.com> writes:

>> On 10/05/16 12:54, Felipe Balbi wrote:

>>>

>>> Hi,

>>>

>>> Roger Quadros <rogerq@ti.com> writes:

>>>> TRM [1] recommends that POWERPRESENT bit must not be

>>>> set and left at it's default value of 0.

>>>>

>>>> [1] OMAP542x TRM - http://www.ti.com/lit/pdf/swpu249

>>>> Section 23.11.4.5.1 Mailbox VBUS/ID Management

>>>>

>>>> "Because PIPE powerpresent has a different meaning in host and in device mode,

>>>> and because of the redundancy with the UTMI signals, the controller ORes

>>>> together the appropriate PIPE and UTMI inputs to create its internal

>>>> VBUS status. For that reason, it is recommended to leave field

>>>> USBOTGSS_UTMI_OTG_STATUS[9] POWERPRESENT at its default value (=0), and only to

>>>> fill in the USB2 VBUS status fields in the same register."

>>>>

>>>> Signed-off-by: Roger Quadros <rogerq@ti.com>

>>>

>>> to make sure we avoid regressions, do you mind sharing on which

>>> platforms you tested this patch ?

>>>

>> I tested this on omap5-uevm and dra7-evm.

>> My am437x board stopped working so couldn't test on that one.

> 

> would you have a colleague or perhaps an automated test-farm which could

> run the test for you ? :-)

> 

> I can take the patch, no problem, but if there are any regressions don't

> blame me :-)

> 

Don't worry, blame is on the TRM then :).

cheers,
-roger
Roger Quadros May 10, 2016, 10:24 a.m. UTC | #3
On 10/05/16 13:04, Felipe Balbi wrote:
> 

> Hi,

> 

> Roger Quadros <rogerq@ti.com> writes:

>> On 10/05/16 12:54, Felipe Balbi wrote:

>>>

>>> Hi,

>>>

>>> Roger Quadros <rogerq@ti.com> writes:

>>>> TRM [1] recommends that POWERPRESENT bit must not be

>>>> set and left at it's default value of 0.

>>>>

>>>> [1] OMAP542x TRM - http://www.ti.com/lit/pdf/swpu249

>>>> Section 23.11.4.5.1 Mailbox VBUS/ID Management

>>>>

>>>> "Because PIPE powerpresent has a different meaning in host and in device mode,

>>>> and because of the redundancy with the UTMI signals, the controller ORes

>>>> together the appropriate PIPE and UTMI inputs to create its internal

>>>> VBUS status. For that reason, it is recommended to leave field

>>>> USBOTGSS_UTMI_OTG_STATUS[9] POWERPRESENT at its default value (=0), and only to

>>>> fill in the USB2 VBUS status fields in the same register."

>>>>

>>>> Signed-off-by: Roger Quadros <rogerq@ti.com>

>>>

>>> to make sure we avoid regressions, do you mind sharing on which

>>> platforms you tested this patch ?

>>>

>> I tested this on omap5-uevm and dra7-evm.

>> My am437x board stopped working so couldn't test on that one.

> 

> would you have a colleague or perhaps an automated test-farm which could

> run the test for you ? :-)


Bin, do you mind testing this and giving your blessings please?

cheers,
-roger
diff mbox

Patch

diff --git a/drivers/usb/dwc3/dwc3-omap.c b/drivers/usb/dwc3/dwc3-omap.c
index a30944d..1f7259d 100644
--- a/drivers/usb/dwc3/dwc3-omap.c
+++ b/drivers/usb/dwc3/dwc3-omap.c
@@ -234,8 +234,7 @@  static void dwc3_omap_set_mailbox(struct dwc3_omap *omap,
 		val &= ~(USBOTGSS_UTMI_OTG_CTRL_IDDIG
 				| USBOTGSS_UTMI_OTG_CTRL_VBUSVALID
 				| USBOTGSS_UTMI_OTG_CTRL_SESSEND);
-		val |= USBOTGSS_UTMI_OTG_CTRL_SESSVALID
-				| USBOTGSS_UTMI_OTG_CTRL_POWERPRESENT;
+		val |= USBOTGSS_UTMI_OTG_CTRL_SESSVALID;
 		dwc3_omap_write_utmi_ctrl(omap, val);
 		break;
 
@@ -244,8 +243,7 @@  static void dwc3_omap_set_mailbox(struct dwc3_omap *omap,
 		val &= ~USBOTGSS_UTMI_OTG_CTRL_SESSEND;
 		val |= USBOTGSS_UTMI_OTG_CTRL_IDDIG
 				| USBOTGSS_UTMI_OTG_CTRL_VBUSVALID
-				| USBOTGSS_UTMI_OTG_CTRL_SESSVALID
-				| USBOTGSS_UTMI_OTG_CTRL_POWERPRESENT;
+				| USBOTGSS_UTMI_OTG_CTRL_SESSVALID;
 		dwc3_omap_write_utmi_ctrl(omap, val);
 		break;
 
@@ -256,8 +254,7 @@  static void dwc3_omap_set_mailbox(struct dwc3_omap *omap,
 	case OMAP_DWC3_VBUS_OFF:
 		val = dwc3_omap_read_utmi_ctrl(omap);
 		val &= ~(USBOTGSS_UTMI_OTG_CTRL_SESSVALID
-				| USBOTGSS_UTMI_OTG_CTRL_VBUSVALID
-				| USBOTGSS_UTMI_OTG_CTRL_POWERPRESENT);
+				| USBOTGSS_UTMI_OTG_CTRL_VBUSVALID);
 		val |= USBOTGSS_UTMI_OTG_CTRL_SESSEND
 				| USBOTGSS_UTMI_OTG_CTRL_IDDIG;
 		dwc3_omap_write_utmi_ctrl(omap, val);