Commit 7604bc29 authored by Maciej W. Rozycki's avatar Maciej W. Rozycki Committed by Bjorn Helgaas
Browse files

PCI: Use pcie_wait_for_link_status() in pcie_wait_for_link_delay() 

Remove a DLLLA status bit polling loop from pcie_wait_for_link_delay() and
call almost identical code in pcie_wait_for_link_status() instead.  This
reduces the lower bound on the polling interval from 10ms to 1ms, possibly
increasing the CPU load on the system in favour to reducing the wait time.

Link: https://lore.kernel.org/r/alpine.DEB.2.21.2306111611170.64925@angie.orcam.me.uk


Signed-off-by: default avatarMaciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 680e9c47

drivers/pci/pci.c

+3 −14
Original line number Diff line number Diff line
@@ -4928,16 +4928,14 @@ bool pcie_retrain_link(struct pci_dev *pdev, bool use_lt) 
static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active,

				     int delay)

{

	int timeout = PCIE_LINK_RETRAIN_TIMEOUT_MS;

	bool ret;

	u16 lnk_status;



	/*

	 * Some controllers might not implement link active reporting. In this

	 * case, we wait for 1000 ms + any delay requested by the caller.

	 */

	if (!pdev->link_active_reporting) {

		msleep(timeout + delay);

		msleep(PCIE_LINK_RETRAIN_TIMEOUT_MS + delay);

		return true;

	}
@@ -4952,20 +4950,11 @@ static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active, 
	 */

	if (active)

		msleep(20);

	for (;;) {

		pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);

		ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);

		if (ret == active)

			break;

		if (timeout <= 0)

			break;

		msleep(10);

		timeout -= 10;

	}

	ret = pcie_wait_for_link_status(pdev, false, active);

	if (active && ret)

		msleep(delay);



	return ret == active;

	return ret;

}



/**