> -----Original Message-----
> From: Damien Le Moal <dlemoal@xxxxxxxxxx>
> Sent: 2024年12月9日 16:48
> To: Hongxing Zhu <hongxing.zhu@xxxxxxx>; jingoohan1@xxxxxxxxx;
> bhelgaas@xxxxxxxxxx; lpieralisi@xxxxxxxxxx; kw@xxxxxxxxx;
> manivannan.sadhasivam@xxxxxxxxxx; robh@xxxxxxxxxx; Frank Li
> <frank.li@xxxxxxx>; quic_krichai@xxxxxxxxxxx
> Cc: imx@xxxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v3 3/3] PCI: dwc: Clean up some unnecessary codes in
> dw_pcie_suspend_noirq()
>
> On 12/9/24 16:39, Richard Zhu wrote:
> > Before sending PME_TURN_OFF, don't test the LTSSM state. Since it's
> > safe to send PME_TURN_OFF message regardless of whether the link is up
> > or down. So, there would be no need to test the LTSSM state before
> > sending PME_TURN_OFF message.
> >
> > Only print the message when ltssm_stat is not in DETECT and POLL.
> > In the other words, there isn't an error message when no endpoint is
> > connected at all.
> >
> > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
> > Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > ---
> > .../pci/controller/dwc/pcie-designware-host.c | 38
> > +++++++++++-------- drivers/pci/controller/dwc/pcie-designware.h |
> > 1 +
> > 2 files changed, 23 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c
> > b/drivers/pci/controller/dwc/pcie-designware-host.c
> > index 14e95c2952bbe..02e0e8c255c70 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> > @@ -982,25 +982,31 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
> > if (dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL) &
> PCI_EXP_LNKCTL_ASPM_L1)
> > return 0;
> >
> > - /* Only send out PME_TURN_OFF when PCIE link is up */
> > - if (dw_pcie_get_ltssm(pci) > DW_PCIE_LTSSM_DETECT_ACT) {
> > - if (pci->pp.ops->pme_turn_off)
> > - pci->pp.ops->pme_turn_off(&pci->pp);
> > - else
> > - ret = dw_pcie_pme_turn_off(pci);
> > -
> > - if (ret)
> > - return ret;
> > + if (pci->pp.ops->pme_turn_off)
> > + pci->pp.ops->pme_turn_off(&pci->pp);
> > + else
> > + ret = dw_pcie_pme_turn_off(pci);
> > + if (ret)
> > + return ret;
>
> ret is always 0 for the "if (pci->pp.ops->pme_turn_off)" case. So this test of "if (ret)
> return ret" should really go inside the "else", and the initialization of ret to 0 on
> declaration can be removed too.
Hi Damien:
Okay, thanks.
BTW, I'm considering that the use-case of #1 patch had been covered by #3
commit already.
To be simple, how about drop the #1 patch, re-format the codes, and add one
Fixes tag into #3?
Best Regards
Richard Zhu
>
> >
> > - ret = read_poll_timeout(dw_pcie_get_ltssm, val, val ==
> DW_PCIE_LTSSM_L2_IDLE,
> > - PCIE_PME_TO_L2_TIMEOUT_US/10,
> > - PCIE_PME_TO_L2_TIMEOUT_US, false, pci);
> > - if (ret) {
> > - dev_err(pci->dev, "Timeout waiting for L2 entry! LTSSM: 0x%x\n",
> val);
> > - return ret;
> > - }
> > + ret = read_poll_timeout(dw_pcie_get_ltssm, val,
> > + val == DW_PCIE_LTSSM_L2_IDLE ||
> > + val <= DW_PCIE_LTSSM_DETECT_WAIT,
> > + PCIE_PME_TO_L2_TIMEOUT_US/10,
> > + PCIE_PME_TO_L2_TIMEOUT_US, false, pci);
> > + if (ret) {
> > + /* Only dump message when ltssm_stat isn't in DETECT and POLL */
> > + dev_err(pci->dev, "Timeout waiting for L2 entry! LTSSM: 0x%x\n", val);
> > + return ret;
> > }
> >
> > + /*
> > + * Refer to r6.0, sec 5.3.3.2.1, software should wait at least
> > + * 100ns after L2/L3 Ready before turning off refclock and
> > + * main power. It's harmless too when no endpoint connected.
> > + */
> > + udelay(1);
> > +
> > dw_pcie_stop_link(pci);
> > if (pci->pp.ops->deinit)
> > pci->pp.ops->deinit(&pci->pp);
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h
> > b/drivers/pci/controller/dwc/pcie-designware.h
> > index 5c14ed2cb91ed..7efcb4af66da3 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -330,6 +330,7 @@ enum dw_pcie_ltssm {
> > /* Need to align with PCIE_PORT_DEBUG0 bits 0:5 */
> > DW_PCIE_LTSSM_DETECT_QUIET = 0x0,
> > DW_PCIE_LTSSM_DETECT_ACT = 0x1,
> > + DW_PCIE_LTSSM_DETECT_WAIT = 0x6,
> > DW_PCIE_LTSSM_L0 = 0x11,
> > DW_PCIE_LTSSM_L2_IDLE = 0x15,
> >
>
>
> --
> Damien Le Moal
> Western Digital Research
