Message ID | 20230814223413.169955-1-CFSworks@gmail.com |
---|---|
State | Accepted |
Commit | d709d4695fd3740025068cc9225755255875f6ad |
Delegated to: | Tom Rini |
Headers | show |
Series | pci: pcie-brcmstb: bring over some robustness improvements from Linux | expand |
On Mon, Aug 14, 2023 at 04:34:13PM -0600, Sam Edwards wrote: > Since the initial U-Boot driver was ported here from Linux, the latter > has had a few changes for robustness/stability. This patch brings over > two of them: > - Do not attempt to access the configuration space of a PCIe device if > the link has gone down, as that will result in an asynchronous SError > interrupt which will crash U-Boot. > - Wait for the recommended 100ms after PERST# is deasserted. > > I sent this patch while debugging a crash involving PCIe, but these > are unrelated improvements. I do not believe that this patch fixes any > real-world bug. > > Signed-off-by: Sam Edwards <CFSworks@gmail.com> Applied to u-boot/next, thanks!
diff --git a/drivers/pci/pcie_brcmstb.c b/drivers/pci/pcie_brcmstb.c index 1de2802113..a159952822 100644 --- a/drivers/pci/pcie_brcmstb.c +++ b/drivers/pci/pcie_brcmstb.c @@ -223,6 +223,10 @@ static int brcm_pcie_config_address(const struct udevice *dev, pci_dev_t bdf, return 0; } + /* An access to our HW w/o link-up will cause a CPU Abort */ + if (!brcm_pcie_link_up(pcie)) + return -EINVAL; + /* For devices, write to the config space index register */ idx = PCIE_ECAM_OFFSET(pci_bus, pci_dev, pci_func, 0); @@ -505,6 +509,12 @@ static int brcm_pcie_probe(struct udevice *dev) clrbits_le32(pcie->base + PCIE_RGR1_SW_INIT_1, RGR1_SW_INIT_1_PERST_MASK); + /* + * Wait for 100ms after PERST# deassertion; see PCIe CEM specification + * sections 2.2, PCIe r5.0, 6.6.1. + */ + mdelay(100); + /* Give the RC/EP time to wake up, before trying to configure RC. * Intermittently check status for link-up, up to a total of 100ms. */
Since the initial U-Boot driver was ported here from Linux, the latter has had a few changes for robustness/stability. This patch brings over two of them: - Do not attempt to access the configuration space of a PCIe device if the link has gone down, as that will result in an asynchronous SError interrupt which will crash U-Boot. - Wait for the recommended 100ms after PERST# is deasserted. I sent this patch while debugging a crash involving PCIe, but these are unrelated improvements. I do not believe that this patch fixes any real-world bug. Signed-off-by: Sam Edwards <CFSworks@gmail.com> --- drivers/pci/pcie_brcmstb.c | 10 ++++++++++ 1 file changed, 10 insertions(+)