[RESEND PATCH v2] PCI: dwc: Round up num_ctrls if num_vectors is less than MAX_MSI_IRQS_PER_CTRL

[Shawn Lin]

On 2022/11/23 6:04, Han Jingoo wrote:
> On Mon, Nov 21, 2022 Shawn Lin <shawn.lin at rock-chips.com> wrote:
>>
>> Some SoCs may only support 1 RC with a few MSIs support that the total number of MSIs is
>> less than MAX_MSI_IRQS_PER_CTRL. In this case, num_ctrls will be zero which fails setting
>> up MSI support. Fix it by rounding up num_ctrls to at least one.
>>
>> Signed-off-by: Shawn Lin <shawn.lin at rock-chips.com>
> 
> Acked-by: Jingoo Han <jingoohan1 at gmail.com>

Thanks, Jingoo!

Hi Lorenzo,

Is there any chance this patch be applied? :)

> 
> Best regards,
> Jingoo Han
> 
>> ---
>>
>> Changes in v2:
>> - set num_ctrls to 1 if it's less than one
>>
>>   drivers/pci/controller/dwc/pcie-designware-host.c | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
>> index 39f3b37..cfce1e0 100644
>> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
>> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
>> @@ -62,6 +62,8 @@ irqreturn_t dw_handle_msi_irq(struct dw_pcie_rp *pp)
>>          struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>>
>>          num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
>> +       if (num_ctrls < 1)
>> +               num_ctrls = 1;
>>
>>          for (i = 0; i < num_ctrls; i++) {
>>                  status = dw_pcie_readl_dbi(pci, PCIE_MSI_INTR0_STATUS +
>> @@ -343,6 +345,8 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
>>          if (!pp->num_vectors)
>>                  pp->num_vectors = MSI_DEF_NUM_VECTORS;
>>          num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
>> +       if (num_ctrls < 1)
>> +               num_ctrls = 1;
>>
>>          if (!pp->msi_irq[0]) {
>>                  pp->msi_irq[0] = platform_get_irq_byname_optional(pdev, "msi");
>> @@ -707,6 +711,8 @@ int dw_pcie_setup_rc(struct dw_pcie_rp *pp)
>>
>>          if (pp->has_msi_ctrl) {
>>                  num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
>> +               if (num_ctrls < 1)
>> +                       num_ctrls = 1;
>>
>>                  /* Initialize IRQ Status array */
>>                  for (ctrl = 0; ctrl < num_ctrls; ctrl++) {
>> --
>> 2.7.4
>>