diff mbox series

mmc: sdhci-msm: Slot indexing for distinguishing multiple SDCC instances

Message ID 20241022141828.618-1-quic_sachgupt@quicinc.com
State New
Headers show
Series mmc: sdhci-msm: Slot indexing for distinguishing multiple SDCC instances | expand

Commit Message

Sachin Gupta Oct. 22, 2024, 2:18 p.m. UTC
This update addresses the requirement for accurate slot indexing
in the sdhci-msm driver to differentiate between multiple SDCC
(Secure Digital Card Controller) instances, such as eMMC, SD card,
and SDIO.

Additionally, it revises the slot indexing logic to comply with
the new device tree (DT) specifications.

Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
Signed-off-by: Sarthak Garg <quic_sartgarg@quicinc.com>
Signed-off-by: Maramaina Naresh <quic_mnaresh@quicinc.com>
Signed-off-by: Ziqi Chen <quic_ziqichen@quicinc.com>
Signed-off-by: Sachin Gupta <quic_sachgupt@quicinc.com>
---
 drivers/mmc/host/sdhci-msm.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Sachin Gupta Oct. 25, 2024, 10:37 a.m. UTC | #1
On 10/24/2024 4:38 PM, Adrian Hunter wrote:
> On 22/10/24 17:18, Sachin Gupta wrote:
>> This update addresses the requirement for accurate slot indexing
>> in the sdhci-msm driver to differentiate between multiple SDCC
>> (Secure Digital Card Controller) instances, such as eMMC, SD card,
>> and SDIO.
>>
>> Additionally, it revises the slot indexing logic to comply with
>> the new device tree (DT) specifications.
> 
> This patch seems incomplete because all it does is assign a global
> variable which is never used again.
> 

Qualcomm internal debugging tools utilize this global variable to
access and differentiate between all the instance's sdhci_msm_host
data structure (eMMC, SD card, and SDIO).

>>
>> Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
>> Signed-off-by: Sarthak Garg <quic_sartgarg@quicinc.com>
>> Signed-off-by: Maramaina Naresh <quic_mnaresh@quicinc.com>
>> Signed-off-by: Ziqi Chen <quic_ziqichen@quicinc.com>
>> Signed-off-by: Sachin Gupta <quic_sachgupt@quicinc.com>
>> ---
>>   drivers/mmc/host/sdhci-msm.c | 10 ++++++++++
>>   1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>> index e113b99a3eab..3cb79117916f 100644
>> --- a/drivers/mmc/host/sdhci-msm.c
>> +++ b/drivers/mmc/host/sdhci-msm.c
>> @@ -292,6 +292,8 @@ struct sdhci_msm_host {
>>   	bool vqmmc_enabled;
>>   };
>>   
>> +static struct sdhci_msm_host *sdhci_slot[3];
>> +
>>   static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
>>   {
>>   	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> @@ -2426,6 +2428,14 @@ static int sdhci_msm_probe(struct platform_device *pdev)
>>   	if (ret)
>>   		goto pltfm_free;
>>   
>> +	if (node) {
>> +		ret = of_alias_get_id(pdev->dev.of_node, "mmc");
>> +		if (ret < 0)
>> +			dev_err(&pdev->dev, "get slot index failed %d\n", ret);
>> +		else
>> +			sdhci_slot[ret] = msm_host;
>> +	}
>> +
>>   	/*
>>   	 * Based on the compatible string, load the required msm host info from
>>   	 * the data associated with the version info.
>
Dmitry Baryshkov Oct. 25, 2024, 10:53 a.m. UTC | #2
On Fri, Oct 25, 2024 at 04:07:52PM +0530, Sachin Gupta wrote:
> 
> 
> On 10/24/2024 4:38 PM, Adrian Hunter wrote:
> > On 22/10/24 17:18, Sachin Gupta wrote:
> > > This update addresses the requirement for accurate slot indexing
> > > in the sdhci-msm driver to differentiate between multiple SDCC
> > > (Secure Digital Card Controller) instances, such as eMMC, SD card,
> > > and SDIO.
> > > 
> > > Additionally, it revises the slot indexing logic to comply with
> > > the new device tree (DT) specifications.
> > 
> > This patch seems incomplete because all it does is assign a global
> > variable which is never used again.
> > 
> 
> Qualcomm internal debugging tools utilize this global variable to
> access and differentiate between all the instance's sdhci_msm_host
> data structure (eMMC, SD card, and SDIO).

"Internal debugging tool". Thank you. NAK from my point of view. It's
upstream kernel, so none of the behind-the-closed-doors tools exist from
its point of view. If you'd consider making it public and open-source,
then we can discuss a best way for it to work.

> > > Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
> > > Signed-off-by: Sarthak Garg <quic_sartgarg@quicinc.com>
> > > Signed-off-by: Maramaina Naresh <quic_mnaresh@quicinc.com>
> > > Signed-off-by: Ziqi Chen <quic_ziqichen@quicinc.com>
> > > Signed-off-by: Sachin Gupta <quic_sachgupt@quicinc.com>
> > > ---
> > >   drivers/mmc/host/sdhci-msm.c | 10 ++++++++++
> > >   1 file changed, 10 insertions(+)
> > > 
> > > diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> > > index e113b99a3eab..3cb79117916f 100644
> > > --- a/drivers/mmc/host/sdhci-msm.c
> > > +++ b/drivers/mmc/host/sdhci-msm.c
> > > @@ -292,6 +292,8 @@ struct sdhci_msm_host {
> > >   	bool vqmmc_enabled;
> > >   };
> > > +static struct sdhci_msm_host *sdhci_slot[3];
> > > +
> > >   static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
> > >   {
> > >   	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > > @@ -2426,6 +2428,14 @@ static int sdhci_msm_probe(struct platform_device *pdev)
> > >   	if (ret)
> > >   		goto pltfm_free;
> > > +	if (node) {
> > > +		ret = of_alias_get_id(pdev->dev.of_node, "mmc");
> > > +		if (ret < 0)
> > > +			dev_err(&pdev->dev, "get slot index failed %d\n", ret);
> > > +		else
> > > +			sdhci_slot[ret] = msm_host;
> > > +	}
> > > +
> > >   	/*
> > >   	 * Based on the compatible string, load the required msm host info from
> > >   	 * the data associated with the version info.
> > 
>
Adrian Hunter Oct. 25, 2024, 12:33 p.m. UTC | #3
On 25/10/24 13:37, Sachin Gupta wrote:
> 
> 
> On 10/24/2024 4:38 PM, Adrian Hunter wrote:
>> On 22/10/24 17:18, Sachin Gupta wrote:
>>> This update addresses the requirement for accurate slot indexing
>>> in the sdhci-msm driver to differentiate between multiple SDCC
>>> (Secure Digital Card Controller) instances, such as eMMC, SD card,
>>> and SDIO.
>>>
>>> Additionally, it revises the slot indexing logic to comply with
>>> the new device tree (DT) specifications.
>>
>> This patch seems incomplete because all it does is assign a global
>> variable which is never used again.
>>
> 
> Qualcomm internal debugging tools utilize this global variable to
> access and differentiate between all the instance's sdhci_msm_host
> data structure (eMMC, SD card, and SDIO).

The kernel does not accept code that does not serve a functional
purpose.

You could look at using eBPF or KGDB to get the information,
otherwise you might just have to carry that kind of patch in
your internal tree.

> 
>>>
>>> Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
>>> Signed-off-by: Sarthak Garg <quic_sartgarg@quicinc.com>
>>> Signed-off-by: Maramaina Naresh <quic_mnaresh@quicinc.com>
>>> Signed-off-by: Ziqi Chen <quic_ziqichen@quicinc.com>
>>> Signed-off-by: Sachin Gupta <quic_sachgupt@quicinc.com>
>>> ---
>>>   drivers/mmc/host/sdhci-msm.c | 10 ++++++++++
>>>   1 file changed, 10 insertions(+)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>>> index e113b99a3eab..3cb79117916f 100644
>>> --- a/drivers/mmc/host/sdhci-msm.c
>>> +++ b/drivers/mmc/host/sdhci-msm.c
>>> @@ -292,6 +292,8 @@ struct sdhci_msm_host {
>>>       bool vqmmc_enabled;
>>>   };
>>>   +static struct sdhci_msm_host *sdhci_slot[3];
>>> +
>>>   static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
>>>   {
>>>       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>> @@ -2426,6 +2428,14 @@ static int sdhci_msm_probe(struct platform_device *pdev)
>>>       if (ret)
>>>           goto pltfm_free;
>>>   +    if (node) {
>>> +        ret = of_alias_get_id(pdev->dev.of_node, "mmc");
>>> +        if (ret < 0)
>>> +            dev_err(&pdev->dev, "get slot index failed %d\n", ret);
>>> +        else
>>> +            sdhci_slot[ret] = msm_host;
>>> +    }
>>> +
>>>       /*
>>>        * Based on the compatible string, load the required msm host info from
>>>        * the data associated with the version info.
>>
>
diff mbox series

Patch

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index e113b99a3eab..3cb79117916f 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -292,6 +292,8 @@  struct sdhci_msm_host {
 	bool vqmmc_enabled;
 };
 
+static struct sdhci_msm_host *sdhci_slot[3];
+
 static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -2426,6 +2428,14 @@  static int sdhci_msm_probe(struct platform_device *pdev)
 	if (ret)
 		goto pltfm_free;
 
+	if (node) {
+		ret = of_alias_get_id(pdev->dev.of_node, "mmc");
+		if (ret < 0)
+			dev_err(&pdev->dev, "get slot index failed %d\n", ret);
+		else
+			sdhci_slot[ret] = msm_host;
+	}
+
 	/*
 	 * Based on the compatible string, load the required msm host info from
 	 * the data associated with the version info.