From: Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>
To: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Philipp Zabel <p.zabel@pengutronix.de>,
Andy Gross <agross@kernel.org>,
Bjorn Andersson <andersson@kernel.org>,
Konrad Dybcio <konrad.dybcio@linaro.org>,
Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Felipe Balbi <balbi@kernel.org>,
"Wesley Cheng" <quic_wcheng@quicinc.com>,
Johan Hovold <johan@kernel.org>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-msm@vger.kernel.org" <linux-arm-msm@vger.kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"quic_pkondeti@quicinc.com" <quic_pkondeti@quicinc.com>,
"quic_ppratap@quicinc.com" <quic_ppratap@quicinc.com>,
"quic_jackp@quicinc.com" <quic_jackp@quicinc.com>,
"quic_harshq@quicinc.com" <quic_harshq@quicinc.com>,
"ahalaney@redhat.com" <ahalaney@redhat.com>,
"quic_shazhuss@quicinc.com" <quic_shazhuss@quicinc.com>
Subject: Re: [PATCH v9 04/10] usb: dwc3: core: Skip setting event buffers for host only controllers
Date: Mon, 3 Jul 2023 00:15:45 +0530 [thread overview]
Message-ID: <9e4ad4b4-60a5-77ec-02ed-183079696e0c@quicinc.com> (raw)
In-Reply-To: <20230626234626.aqhaluh6wnat6gxx@synopsys.com>
On 6/27/2023 5:16 AM, Thinh Nguyen wrote:
> On Mon, Jun 26, 2023, Thinh Nguyen wrote:
>> On Sat, Jun 24, 2023, Krishna Kurapati PSSNV wrote:
>>>
>>>
>>> On 6/24/2023 3:57 AM, Thinh Nguyen wrote:
>>>> On Wed, Jun 21, 2023, Krishna Kurapati wrote:
>>>>> On some SoC's like SA8295P where the tertiary controller is host-only
>>>>> capable, GEVTADDRHI/LO, GEVTSIZ, GEVTCOUNT registers are not accessible.
>>>>> Trying to access them leads to a crash.
>>>>>
>>>>> For DRD/Peripheral supported controllers, event buffer setup is done
>>>>> again in gadget_pullup. Skip setup or cleanup of event buffers if
>>>>> controller is host-only capable.
>>>>>
>>>>> Suggested-by: Johan Hovold <johan@kernel.org>
>>>>> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
>>>>> ---
>>>>> drivers/usb/dwc3/core.c | 11 +++++++++++
>>>>> 1 file changed, 11 insertions(+)
>>>>>
>>>>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>>>>> index 32ec05fc242b..e1ebae54454f 100644
>>>>> --- a/drivers/usb/dwc3/core.c
>>>>> +++ b/drivers/usb/dwc3/core.c
>>>>> @@ -486,6 +486,11 @@ static void dwc3_free_event_buffers(struct dwc3 *dwc)
>>>>> static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned int length)
>>>>> {
>>>>> struct dwc3_event_buffer *evt;
>>>>> + unsigned int hw_mode;
>>>>> +
>>>>> + hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
>>>>> + if (hw_mode == DWC3_GHWPARAMS0_MODE_HOST)
>>>>> + return 0;
>>>>
>>>> This is a little awkward. Returning 0 here indicates that this function
>>>> was successful, and the event buffers were allocated based on the
>>>> function name. Do this check outside of dwc3_alloc_one_event_buffer()
>>>> and specifically set dwc->ev_buf = NULL if that's the case.
>>>>
>>> Hi Thinh,
>>>
>>> Apologies, I didn't understand the comment properly.
>>>
>>> I thought we were supposed to return 0 here if we fulfill the goal of this
>>> function (allocate if we are drd/gadget and don't allocate if we are host
>>> mode only).
>>
>> The name of the function implies that it returns 0 if it allocated the
>> event buffer. If there are multiple conditions to the function returning
>> 0 here, then we should document it.
>>
>>>
>>> If we return a non zero error here, probe would fail as this call will be
>>> done only for host only controllers during probe and nowhere else.
>>>
>>> Are you suggesting we move this check to dwc3_alloc_one_event_buffer call
>>> ?
>>>
>>> Regards,
>>> Krishna,
>>>
>>
>> I'm suggesting to move the check to the caller of
>> dwc3_alloc_one_event_buffer(). Something like this so that it's
>> self-documented:
>>
>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>> index 0beaab932e7d..bba82792bf6f 100644
>> --- a/drivers/usb/dwc3/core.c
>> +++ b/drivers/usb/dwc3/core.c
>> @@ -1773,6 +1773,7 @@ static int dwc3_probe(struct platform_device *pdev)
>> struct resource *res, dwc_res;
>> void __iomem *regs;
>> struct dwc3 *dwc;
>> + unsigned int hw_mode;
>> int ret;
>>
>> dwc = devm_kzalloc(dev, sizeof(*dwc), GFP_KERNEL);
>> @@ -1854,11 +1855,16 @@ static int dwc3_probe(struct platform_device *pdev)
>>
>> pm_runtime_forbid(dev);
>>
>> - ret = dwc3_alloc_event_buffers(dwc, DWC3_EVENT_BUFFERS_SIZE);
>> - if (ret) {
>> - dev_err(dwc->dev, "failed to allocate event buffers\n");
>> - ret = -ENOMEM;
>> - goto err_allow_rpm;
>> + hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
>> + if (hw_mode == DWC3_GHWPARAMS0_MODE_HOST) {
>> + dwc->ev_buf = NULL;
>> + } else {
>> + ret = dwc3_alloc_event_buffers(dwc, DWC3_EVENT_BUFFERS_SIZE);
>> + if (ret) {
>> + dev_err(dwc->dev, "failed to allocate event buffers\n");
>> + ret = -ENOMEM;
>> + goto err_allow_rpm;
>> + }
>> }
>>
>> dwc->edev = dwc3_get_extcon(dwc);
>>
>
> Actually, please ignore. there's already a document there, I missed that
> for some reason. What you did is fine. Though, I don't see the condition
> for ev_buf = NULL anywhere. Can you add that for clarity?
>
> Thanks,
> Thinh
Hi Thinh,
Did you mean adding "dwc->ev_buf = NULL" specifically ?
Regards,
Krishna,
next prev parent reply other threads:[~2023-07-02 18:46 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-21 4:36 [PATCH v9 00/10] Add multiport support for DWC3 controllers Krishna Kurapati
2023-06-21 4:36 ` [PATCH v9 01/10] dt-bindings: usb: qcom,dwc3: Add bindings for SC8280 Multiport Krishna Kurapati
2023-06-23 20:41 ` Rob Herring
2023-06-27 11:20 ` Johan Hovold
2023-06-27 15:38 ` Johan Hovold
2023-07-02 19:11 ` Krishna Kurapati PSSNV
2023-07-21 8:10 ` Johan Hovold
2023-06-21 4:36 ` [PATCH v9 02/10] dt-bindings: usb: Add bindings for multiport properties on DWC3 controller Krishna Kurapati
2023-06-23 20:41 ` Rob Herring
2023-06-27 11:24 ` Johan Hovold
2023-06-21 4:36 ` [PATCH v9 03/10] usb: dwc3: core: Access XHCI address space temporarily to read port info Krishna Kurapati
2023-06-23 22:14 ` Thinh Nguyen
2023-06-27 11:45 ` Johan Hovold
2023-07-02 18:48 ` Krishna Kurapati PSSNV
2023-07-21 7:44 ` Johan Hovold
2023-07-23 14:59 ` Krishna Kurapati PSSNV
2023-07-24 15:41 ` Johan Hovold
2023-07-25 5:39 ` Krishna Kurapati PSSNV
2023-06-21 4:36 ` [PATCH v9 04/10] usb: dwc3: core: Skip setting event buffers for host only controllers Krishna Kurapati
2023-06-23 22:27 ` Thinh Nguyen
2023-06-24 7:20 ` Krishna Kurapati PSSNV
2023-06-26 23:34 ` Thinh Nguyen
2023-06-26 23:46 ` Thinh Nguyen
2023-07-02 18:45 ` Krishna Kurapati PSSNV [this message]
2023-07-05 22:40 ` Thinh Nguyen
2023-06-21 4:36 ` [PATCH v9 05/10] usb: dwc3: core: Refactor PHY logic to support Multiport Controller Krishna Kurapati
2023-06-23 22:55 ` Thinh Nguyen
2023-06-24 7:15 ` Krishna Kurapati PSSNV
2023-06-27 12:09 ` Johan Hovold
2023-07-02 18:56 ` Krishna Kurapati PSSNV
2023-07-21 7:56 ` Johan Hovold
2023-08-01 1:30 ` Thinh Nguyen
2023-10-19 13:20 ` Johan Hovold
2023-06-21 4:36 ` [PATCH v9 06/10] usb: dwc3: qcom: Add support to read IRQ's related to multiport Krishna Kurapati
2023-06-21 10:05 ` Konrad Dybcio
2023-06-21 10:08 ` Krishna Kurapati PSSNV
2023-06-27 14:31 ` Johan Hovold
2023-07-02 18:59 ` Krishna Kurapati PSSNV
2023-07-11 6:42 ` Krishna Kurapati PSSNV
2023-07-21 8:14 ` Johan Hovold
2023-07-21 8:19 ` Krishna Kurapati PSSNV
2023-07-21 9:21 ` Johan Hovold
2023-07-21 9:35 ` Krishna Kurapati PSSNV
2023-07-21 11:11 ` Johan Hovold
2023-07-12 12:12 ` Johan Hovold
2023-07-12 18:26 ` Krishna Kurapati PSSNV
2023-07-14 9:05 ` Johan Hovold
2023-07-14 10:40 ` Krishna Kurapati PSSNV
2023-07-15 19:01 ` Krishna Kurapati PSSNV
2023-07-17 15:15 ` Krishna Kurapati PSSNV
2023-07-21 8:35 ` Johan Hovold
2023-07-21 8:45 ` Krishna Kurapati PSSNV
2023-06-21 4:36 ` [PATCH v9 07/10] usb: dwc3: qcom: Add multiport suspend/resume support for wrapper Krishna Kurapati
2023-06-27 15:05 ` Johan Hovold
2023-07-02 19:02 ` Krishna Kurapati PSSNV
2023-06-21 4:36 ` [PATCH v9 08/10] arm64: dts: qcom: sc8280xp: Add multiport controller node for SC8280 Krishna Kurapati
2023-06-23 22:39 ` Konrad Dybcio
2023-06-24 7:13 ` Krishna Kurapati PSSNV
2023-06-27 15:16 ` Johan Hovold
2023-07-02 19:10 ` Krishna Kurapati PSSNV
2023-07-21 8:08 ` Johan Hovold
2023-06-27 15:11 ` Johan Hovold
2023-06-21 4:36 ` [PATCH v9 09/10] arm64: dts: qcom: sa8295p: Enable tertiary controller and its 4 USB ports Krishna Kurapati
2023-06-23 22:40 ` Konrad Dybcio
2023-06-21 4:36 ` [PATCH v9 10/10] arm64: dts: qcom: sa8540-ride: Enable first port of tertiary usb controller Krishna Kurapati
2023-06-23 22:42 ` Konrad Dybcio
2023-06-24 7:11 ` Krishna Kurapati PSSNV
2023-06-27 15:19 ` [PATCH v9 00/10] Add multiport support for DWC3 controllers Johan Hovold
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