Hi,

Felipe Balbi <felipe.ba...@linux.intel.com> writes:
> Felipe Balbi <felipe.ba...@linux.intel.com> writes:
>> Synopsys Databook 2.60a has a note that if we're
>> sending a Start Transfer command we _must_ make sure
>> that DWC3_GUSB2PHY(n).SUSPHY bit is cleared.
>>
>> This patch implements that particular detail.
>>
>> Signed-off-by: Felipe Balbi <felipe.ba...@linux.intel.com>
>> ---
>>  drivers/usb/dwc3/gadget.c | 25 +++++++++++++++++++++++++
>>  1 file changed, 25 insertions(+)
>>
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index 0967b5d8fb75..8b3a676db346 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -227,10 +227,29 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned 
>> ep,
>>      struct dwc3_ep          *dep = dwc->eps[ep];
>>      u32                     timeout = 500;
>>      u32                     reg;
>> +
>> +    int                     susphy = false;
>>      int                     ret = -EINVAL;
>>  
>>      trace_dwc3_gadget_ep_cmd(dep, cmd, params);
>>  
>> +    /*
>> +     * Synopsys Databook 2.60a states, on section 6.3.2.5.5, that if we're
>> +     * issuing a Start Transfer command, we must check if GUSB2PHYCFG.SUSPHY
>> +     * bit is set. If it is, then we need to clear it.
>> +     *
>> +     * We will also set SUSPHY bit to what it was before returning as stated
>> +     * by the same section on Synopsys databook.
>> +     */
>> +    if (cmd == DWC3_DEPCMD_STARTTRANSFER) {
>
> After digging a little deeper, every command needs this, not only Start
> Transfer. I'll remove this check.

Here's v2, I've pushed it to testing/next:

8<----------------------------------------------------------------
From 81b72307545522bb962f2ebbb49be8fef1ffa547 Mon Sep 17 00:00:00 2001
From: Felipe Balbi <felipe.ba...@linux.intel.com>
Date: Mon, 4 Apr 2016 09:19:17 +0300
Subject: [PATCH v2] usb: dwc3: gadget: clear SUSPHY bit before ep cmds

Synopsys Databook 2.60a has a note that if we're
sending an endpoint command we _must_ make sure that
DWC3_GUSB2PHY(n).SUSPHY bit is cleared.

This patch implements that particular detail.

Signed-off-by: Felipe Balbi <felipe.ba...@linux.intel.com>
---

changes since v1:
        - clear SUSPHY for all endpoint commands

 drivers/usb/dwc3/gadget.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 0967b5d8fb75..7b8c1c8574f9 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -227,10 +227,27 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
        struct dwc3_ep          *dep = dwc->eps[ep];
        u32                     timeout = 500;
        u32                     reg;
+
+       int                     susphy = false;
        int                     ret = -EINVAL;
 
        trace_dwc3_gadget_ep_cmd(dep, cmd, params);
 
+       /*
+        * Synopsys Databook 2.60a states, on section 6.3.2.5.[1-8], that if
+        * we're issuing an endpoint command, we must check if
+        * GUSB2PHYCFG.SUSPHY bit is set. If it is, then we need to clear it.
+        *
+        * We will also set SUSPHY bit to what it was before returning as stated
+        * by the same section on Synopsys databook.
+        */
+       reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+       if (unlikely(reg & DWC3_GUSB2PHYCFG_SUSPHY)) {
+               susphy = true;
+               reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
+               dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+       }
+
        dwc3_writel(dwc->regs, DWC3_DEPCMDPAR0(ep), params->param0);
        dwc3_writel(dwc->regs, DWC3_DEPCMDPAR1(ep), params->param1);
        dwc3_writel(dwc->regs, DWC3_DEPCMDPAR2(ep), params->param2);
@@ -263,6 +280,12 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
                udelay(1);
        } while (1);
 
+       if (unlikely(susphy)) {
+               reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+               reg |= DWC3_GUSB2PHYCFG_SUSPHY;
+               dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+       }
+
        return ret;
 }
 
-- 
2.8.0.rc2



-- 
balbi

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