On Fri, Jan 07, 2022 at 03:12:45AM +0000, Hongxing Zhu wrote:
-----Original Message----- From: Fabio Estevam festevam@gmail.com Sent: Thursday, January 6, 2022 6:37 PM To: bhelgaas@google.com Cc: lorenzo.pieralisi@arm.com; robh@kernel.org; l.stach@pengutronix.de; Hongxing Zhu hongxing.zhu@nxp.com; linux-pci@vger.kernel.org; Fabio Estevam festevam@gmail.com; stable@vger.kernel.org Subject: [PATCH v2] PCI: imx6: Allow to probe when dw_pcie_wait_for_link() fails
The intention of commit 886a9c134755 ("PCI: dwc: Move link handling into common code") was to standardize the behavior of link down as explained in its commit log:
"The behavior for a link down was inconsistent as some drivers would fail probe in that case while others succeed. Let's standardize this to succeed as there are usecases where devices (and the link) appear later even without hotplug. For example, a reconfigured FPGA device."
The pci-imx6 still fails to probe when the link is not present, which causes the following warning:
imx6q-pcie 8ffc000.pcie: Phy link never came up imx6q-pcie: probe of 8ffc000.pcie failed with error -110 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 30 at drivers/regulator/core.c:2257 _regulator_put.part.0+0x1b8/0x1dc Modules linked in: CPU: 0 PID: 30 Comm: kworker/u2:2 Not tainted 5.15.0-next-20211103 #1 Hardware name: Freescale i.MX6 SoloX (Device Tree) Workqueue: events_unbound async_run_entry_fn [<c0111730>] (unwind_backtrace) from [<c010bb74>] (show_stack+0x10/0x14) [<c010bb74>] (show_stack) from [<c0f90290>] (dump_stack_lvl+0x58/0x70) [<c0f90290>] (dump_stack_lvl) from [<c012631c>] (__warn+0xd4/0x154) [<c012631c>] (__warn) from [<c0f87b00>] (warn_slowpath_fmt+0x74/0xa8) [<c0f87b00>] (warn_slowpath_fmt) from [<c076b4bc>] (_regulator_put.part.0+0x1b8/0x1dc) [<c076b4bc>] (_regulator_put.part.0) from [<c076b574>] (regulator_put+0x2c/0x3c) [<c076b574>] (regulator_put) from [<c08c3740>] (release_nodes+0x50/0x178)
Fix this problem by ignoring the dw_pcie_wait_for_link() error like it is done on the other dwc drivers.
Tested on imx6sx-sdb and imx6q-sabresd boards.
Cc: stable@vger.kernel.org Fixes: 886a9c134755 ("PCI: dwc: Move link handling into common code") Signed-off-by: Fabio Estevam festevam@gmail.com
[Richard Zhu] Reviewed-by: Richard Zhu hongxing.zhu@nxp.com
Please, there is no need to add [Richard Zhu] to let us understand it is you, this breaks tools that pick up tags automatically so refrain from using it, thanks.
Lorenzo
Changes since v1:
- Remove the printk timestamp from the kernel warning log (Richard).
drivers/pci/controller/dwc/pci-imx6.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index 2ac081510632..5e8a03061b31 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -807,9 +807,7 @@ static int imx6_pcie_start_link(struct dw_pcie *pci) /* Start LTSSM. */ imx6_pcie_ltssm_enable(dev);
- ret = dw_pcie_wait_for_link(pci);
- if (ret)
goto err_reset_phy;
dw_pcie_wait_for_link(pci);
if (pci->link_gen == 2) { /* Allow Gen2 mode after the link is up. */ @@ -845,11 +843,7
@@ static int imx6_pcie_start_link(struct dw_pcie *pci) }
/* Make sure link training is finished as well! */
ret = dw_pcie_wait_for_link(pci);if (ret) {dev_err(dev, "Failed to bring link up!\n");goto err_reset_phy;}
dw_pcie_wait_for_link(pci);-- 2.25.1