Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 68bc10bf authored by Trent Piepho's avatar Trent Piepho Committed by Lorenzo Pieralisi
Browse files

PCI: imx6: Fix link training status detection in link up check 



This bug was introduced in the interaction for two commits on either
branch of the merge commit 562df5c8 ("Merge branch
'pci/host-designware' into next").

Commit 4d107d3b ("PCI: imx6: Move link up check into
imx6_pcie_wait_for_link()"), changed imx6_pcie_wait_for_link() to poll
the link status register directly, checking for link up and not
training, and made imx6_pcie_link_up() only check the link up bit (once,
not a polling loop).

While commit 886bc5ce ("PCI: designware: Add generic
dw_pcie_wait_for_link()"), replaced the loop in
imx6_pcie_wait_for_link() with a call to a new dwc core function, which
polled imx6_pcie_link_up(), which still checked both link up and not
training in a loop.

When these two commits were merged, the version of
imx6_pcie_wait_for_link() from 886bc5ce was kept, which eliminated
the link training check placed there by 4d107d3b. However, the
version of imx6_pcie_link_up() from 4d107d3b was kept, which
eliminated the link training check that had been there and was moved to
imx6_pcie_wait_for_link().

The result was the link training check got lost for the imx6 driver.

Eliminate imx6_pcie_link_up() so that the default handler,
dw_pcie_link_up(), is used instead. The default handler has the correct
code, which checks for link up and also that it still is not training,
fixing the regression.

Fixes: 562df5c8 ("Merge branch 'pci/host-designware' into next")
Signed-off-by: default avatarTrent Piepho <tpiepho@impinj.com>
[lorenzo.pieralisi@arm.com: rewrote the commit log]
Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: default avatarLucas Stach <l.stach@pengutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Joao Pinto <Joao.Pinto@synopsys.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Richard Zhu <hongxing.zhu@nxp.com>
parent 65102238

drivers/pci/controller/dwc/pci-imx6.c

+1 −9
Original line number Diff line number Diff line
@@ -81,8 +81,6 @@ struct imx6_pcie { 
#define PCIE_PL_PFLR_FORCE_LINK			(1 << 15)

#define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)

#define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)

#define PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING	(1 << 29)

#define PCIE_PHY_DEBUG_R1_XMLH_LINK_UP		(1 << 4)



#define PCIE_PHY_CTRL (PL_OFFSET + 0x114)

#define PCIE_PHY_CTRL_DATA_LOC 0
@@ -711,12 +709,6 @@ static int imx6_pcie_host_init(struct pcie_port *pp) 
	return 0;

}



static int imx6_pcie_link_up(struct dw_pcie *pci)

{

	return dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1) &

			PCIE_PHY_DEBUG_R1_XMLH_LINK_UP;

}



static const struct dw_pcie_host_ops imx6_pcie_host_ops = {

	.host_init = imx6_pcie_host_init,

};
@@ -749,7 +741,7 @@ static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie, 
}



static const struct dw_pcie_ops dw_pcie_ops = {

	.link_up = imx6_pcie_link_up,

	/* No special ops needed, but pcie-designware still expects this struct */

};



#ifdef CONFIG_PM_SLEEP