From: Marc Gonzalez <marc.w.gonzalez@free.fr>
To: Stanimir Varbanov <svarbanov@mm-sol.com>,
Bjorn Helgaas <bhelgaas@google.com>
Cc: Andy Gross <andy.gross@linaro.org>,
David Brown <david.brown@linaro.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
PCI <linux-pci@vger.kernel.org>,
MSM <linux-arm-msm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Jeffrey Hugo <jhugo@codeaurora.org>
Subject: Re: [RFC PATCH v1] PCI: qcom: Use quirk to override incorrect device class
Date: Tue, 12 Mar 2019 18:18:40 +0100 [thread overview]
Message-ID: <1205cbfb-ac06-63a5-9401-75d4e68b15b5@free.fr> (raw)
In-Reply-To: <65321fe3-ca29-c454-63ae-98a46c2e5158@mm-sol.com>
On 12/03/2019 13:42, Stanimir Varbanov wrote:
> On 3/11/19 4:56 PM, Marc Gonzalez wrote:
>
>> Some chips report an incorrect device class. Override the incorrect
>> value using a quirk, instead of code in the read function.
>>
>> Signed-off-by: Marc Gonzalez <marc.w.gonzalez@free.fr>
>> ---
>> FWIW, this quirk is no longer required on recent chips:
>> msm8996 (tested by Stanimir), msm8998 (tested by me), sdm845 (untested) are unaffected
>> apq/ipq8064 is affected => what is the device ID for these chips?
>> others?
>>
>> Stanimir added: "this will become a real problem (now we use the driver as RC)
>> when someone decide to use it as an endpoint"
>> ---
>> drivers/pci/controller/dwc/pcie-qcom.c | 14 ++++++--------
>> 1 file changed, 6 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
>> index 3de5510fd3d5..94da2c9c2ad5 100644
>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
>> @@ -1136,17 +1136,15 @@ static int qcom_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
>> {
>> struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>>
>> - /* the device class is not reported correctly from the register */
>> - if (where == PCI_CLASS_REVISION && size == 4) {
>> - *val = readl(pci->dbi_base + PCI_CLASS_REVISION);
>> - *val &= 0xff; /* keep revision id */
>> - *val |= PCI_CLASS_BRIDGE_PCI << 16;
>> - return PCIBIOS_SUCCESSFUL;
>> - }
>> -
>
> once you dropped the above snippet this function becomes absolutely
> useless so please delete it at all and also from qcom_pcie_dw_ops.
Good catch.
>> return dw_pcie_read(pci->dbi_base + where, size, val);
>> }
>>
>> +static void qcom_fixup_class(struct pci_dev *dev)
>> +{
>> + dev->class = PCI_CLASS_BRIDGE_PCI << 8;
>> +}
>> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, PCI_ANY_ID, qcom_fixup_class);
>
> I wonder, in case that dw_pcie_setup_rc() already has a write to
> PCI_CLASS_DEVICE configuration register to set it as a bridge do we
> still need to do the above fixup?
I don't know, I don't have an affected device. Unless the msm8998 /is/ affected,
and dw_pcie_setup_rc() actually fixes it?
Regards.
next prev parent reply other threads:[~2019-03-12 17:19 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-11 14:56 [RFC PATCH v1] PCI: qcom: Use quirk to override incorrect device class Marc Gonzalez
2019-03-12 12:42 ` Stanimir Varbanov
2019-03-12 17:18 ` Marc Gonzalez [this message]
2019-03-12 17:34 ` Marc Gonzalez
2019-03-13 11:45 ` [PATCH v2] PCI: qcom: Use default config space read function Marc Gonzalez
2019-03-13 13:13 ` Marc Gonzalez
2019-03-13 18:29 ` Srinivas Kandagatla
2019-03-13 20:39 ` Marc Gonzalez
2019-03-13 21:52 ` Srinivas Kandagatla
2019-03-13 22:26 ` Marc Gonzalez
2019-03-14 11:10 ` Srinivas Kandagatla
2019-03-14 13:18 ` Marc Gonzalez
2019-03-18 14:28 ` [PATCH v3] " Marc Gonzalez
2019-03-18 14:39 ` Srinivas Kandagatla
2019-03-18 16:35 ` Stanimir Varbanov
2019-03-18 17:14 ` [PATCH v4] " Marc Gonzalez
2019-03-25 12:11 ` Marc Gonzalez
2019-03-25 13:32 ` Stanimir Varbanov
2019-03-25 15:42 ` [PATCH v5] " Marc Gonzalez
2019-03-29 13:48 ` Marc Gonzalez
2019-03-29 15:55 ` Stanimir Varbanov
2019-03-29 16:38 ` Lorenzo Pieralisi
2019-04-01 10:39 ` Marc Gonzalez
2019-04-01 11:12 ` Lorenzo Pieralisi
2019-04-30 14:06 ` [RFC PATCH v1] PCI: qcom: Use quirk to override incorrect device class Lorenzo Pieralisi
2019-05-02 9:42 ` Marc Gonzalez
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