Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: bbhatt=codeaurora.org@mg.codeaurora.org
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII;
 format=flowed
Content-Transfer-Encoding: 7bit
Date:   Fri, 18 Jun 2021 10:41:34 -0700
From:   Bhaumik Bhatt <bbhatt@codeaurora.org>
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc:     linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org,
        jhugo@codeaurora.org, linux-kernel@vger.kernel.org,
        carl.yin@quectel.com, naveen.kumar@quectel.com,
        loic.poulain@linaro.org
Subject: Re: [PATCH] bus: mhi: pci_generic: Apply no-op for wake using inband
 wake support flag
Organization: Qualcomm Innovation Center, Inc.
Reply-To: bbhatt@codeaurora.org
Mail-Reply-To: bbhatt@codeaurora.org
In-Reply-To: <20210618172746.GA30140@workstation>
References: <1623954233-32092-1-git-send-email-bbhatt@codeaurora.org>
 <20210618065249.GN3682@workstation>
 <83d12d5cc46ef7fda12caf7e3bdfddd1@codeaurora.org>
 <20210618172746.GA30140@workstation>
Message-ID: <e568a1f1db7325800b6e43f3526be2fd@codeaurora.org>
User-Agent: Roundcube Webmail/1.3.9
Precedence: bulk

On 2021-06-18 10:27 AM, Manivannan Sadhasivam wrote:
> On Fri, Jun 18, 2021 at 10:06:28AM -0700, Bhaumik Bhatt wrote:
>> Hi Mani,
>> On 2021-06-17 11:52 PM, Manivannan Sadhasivam wrote:
>> > On Thu, Jun 17, 2021 at 11:23:53AM -0700, Bhaumik Bhatt wrote:
>> > > Devices such as SDX24 do not have the provision for inband wake
>> > > doorbell in the form of channel 127. Newer devices such as SDX55
>> > > or SDX65 have it by default. Ensure the functionality is used
>> > > based on this such that device wake stays held when a client
>> > > driver uses mhi_device_get() API or the equivalent debugfs entry.
>> > >
>> > > Fixes: e3e5e6508fc1 ("bus: mhi: pci_generic: No-Op for device_wake
>> > > operations")
>> > > Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
>> > > ---
>> > >  drivers/bus/mhi/pci_generic.c | 26 ++++++++++++++++++--------
>> > >  1 file changed, 18 insertions(+), 8 deletions(-)
>> > >
>> > > diff --git a/drivers/bus/mhi/pci_generic.c
>> > > b/drivers/bus/mhi/pci_generic.c
>> > > index d84b743..31360a2 100644
>> > > --- a/drivers/bus/mhi/pci_generic.c
>> > > +++ b/drivers/bus/mhi/pci_generic.c
>> > > @@ -32,6 +32,7 @@
>> > >   * @edl: emergency download mode firmware path (if any)
>> > >   * @bar_num: PCI base address register to use for MHI MMIO register
>> > > space
>> > >   * @dma_data_width: DMA transfer word size (32 or 64 bits)
>> > > + * @no_inband_wake: Devices without inband wake support (such as
>> > > sdx24)
>> >
>> > I'd rather like this field to be "inband_wake" and set to false/true
>> > based on the capability of the devices. Rest looks good.
>> >
>> > Thanks,
>> > Mani
>> >
>> I should have known this was coming :)
>> 
>> Can I use sideband_wake instead of no_inband_wake and leave the 
>> booleans as
>> is?
> 
> Do you mean, the older devices uses a dedicated sideband GPIO for
> controlling the wakeup? If so, what is it?
> 
 From what I know, this used to be the DEVICE_WAKE GPIO for SDX24. We 
moved to use
the channel 127 doorbell as WAKE doorbell for this purpose SDX55 onwards 
for ease
of deployment.

>> By default, inband_wake will have to be true for any and all devices 
>> moving
>> forward.
>> 
> 
> Right but still the functionality is not present in older devices. So I
> think it makes sense to stay with "inband_wake".
> 
> Thanks,
> Mani
> 
So, by default we would not have to add explicit "true" for inband_wake 
as
newer devices will have the feature and controller drivers do not need 
to
populate the entry for a static const struct.

>> Please let me know your preference.
>> > >   */
>> > >  struct mhi_pci_dev_info {
>> > >  	const struct mhi_controller_config *config;
>> > > @@ -40,6 +41,7 @@ struct mhi_pci_dev_info {
>> > >  	const char *edl;
>> > >  	unsigned int bar_num;
>> > >  	unsigned int dma_data_width;
>> > > +	bool no_inband_wake;
>> > >  };
>> > >
>> > >  #define MHI_CHANNEL_CONFIG_UL(ch_num, ch_name, el_count, ev_ring) \
>> > > @@ -242,7 +244,8 @@ static const struct mhi_pci_dev_info
>> > > mhi_qcom_sdx65_info = {
>> > >  	.edl = "qcom/sdx65m/edl.mbn",
>> > >  	.config = &modem_qcom_v1_mhiv_config,
>> > >  	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
>> > > -	.dma_data_width = 32
>> > > +	.dma_data_width = 32,
>> > > +	.no_inband_wake = false
>> > >  };
>> > >
>> > >  static const struct mhi_pci_dev_info mhi_qcom_sdx55_info = {
>> > > @@ -251,7 +254,8 @@ static const struct mhi_pci_dev_info
>> > > mhi_qcom_sdx55_info = {
>> > >  	.edl = "qcom/sdx55m/edl.mbn",
>> > >  	.config = &modem_qcom_v1_mhiv_config,
>> > >  	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
>> > > -	.dma_data_width = 32
>> > > +	.dma_data_width = 32,
>> > > +	.no_inband_wake = false
>> > >  };
>> > >
>> > >  static const struct mhi_pci_dev_info mhi_qcom_sdx24_info = {
>> > > @@ -259,7 +263,8 @@ static const struct mhi_pci_dev_info
>> > > mhi_qcom_sdx24_info = {
>> > >  	.edl = "qcom/prog_firehose_sdx24.mbn",
>> > >  	.config = &modem_qcom_v1_mhiv_config,
>> > >  	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
>> > > -	.dma_data_width = 32
>> > > +	.dma_data_width = 32,
>> > > +	.no_inband_wake = true
>> > >  };
>> > >
>> > >  static const struct mhi_channel_config mhi_quectel_em1xx_channels[]
>> > > = {
>> > > @@ -301,7 +306,8 @@ static const struct mhi_pci_dev_info
>> > > mhi_quectel_em1xx_info = {
>> > >  	.edl = "qcom/prog_firehose_sdx24.mbn",
>> > >  	.config = &modem_quectel_em1xx_config,
>> > >  	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
>> > > -	.dma_data_width = 32
>> > > +	.dma_data_width = 32,
>> > > +	.no_inband_wake = true
>> > >  };
>> > >
>> > >  static const struct mhi_channel_config mhi_foxconn_sdx55_channels[]
>> > > = {
>> > > @@ -339,7 +345,8 @@ static const struct mhi_pci_dev_info
>> > > mhi_foxconn_sdx55_info = {
>> > >  	.edl = "qcom/sdx55m/edl.mbn",
>> > >  	.config = &modem_foxconn_sdx55_config,
>> > >  	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
>> > > -	.dma_data_width = 32
>> > > +	.dma_data_width = 32,
>> > > +	.no_inband_wake = false
>> > >  };
>> > >
>> > >  static const struct pci_device_id mhi_pci_id_table[] = {
>> > > @@ -640,9 +647,12 @@ static int mhi_pci_probe(struct pci_dev *pdev,
>> > > const struct pci_device_id *id)
>> > >  	mhi_cntrl->status_cb = mhi_pci_status_cb;
>> > >  	mhi_cntrl->runtime_get = mhi_pci_runtime_get;
>> > >  	mhi_cntrl->runtime_put = mhi_pci_runtime_put;
>> > > -	mhi_cntrl->wake_get = mhi_pci_wake_get_nop;
>> > > -	mhi_cntrl->wake_put = mhi_pci_wake_put_nop;
>> > > -	mhi_cntrl->wake_toggle = mhi_pci_wake_toggle_nop;
>> > > +
>> > > +	if (info->no_inband_wake) {
>> > > +		mhi_cntrl->wake_get = mhi_pci_wake_get_nop;
>> > > +		mhi_cntrl->wake_put = mhi_pci_wake_put_nop;
>> > > +		mhi_cntrl->wake_toggle = mhi_pci_wake_toggle_nop;
>> > > +	}
>> > >
>> > >  	err = mhi_pci_claim(mhi_cntrl, info->bar_num,
>> > > DMA_BIT_MASK(info->dma_data_width));
>> > >  	if (err)
>> > > --
>> > > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
>> > > Forum,
>> > > a Linux Foundation Collaborative Project
>> > >
>> 
>> Thanks,
>> Bhaumik
>> ---
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>> a Linux Foundation Collaborative Project

Thanks,
Bhaumik
---
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
Forum,
a Linux Foundation Collaborative Project