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author | Oza Pawandeep <oza.oza@broadcom.com> | 2017-08-29 00:43:35 +0300 |
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committer | Bjorn Helgaas <bhelgaas@google.com> | 2017-09-05 20:27:03 +0300 |
commit | b91c26c6a539e26261cbe280b9f48311663ce655 (patch) | |
tree | e27ec47aabff5110f85dd1e894c66c6a5ea964d1 /drivers/pci/host/pcie-iproc.h | |
parent | 39b7a4ff930143f17d05cd769ba2099f9249e898 (diff) | |
download | linux-b91c26c6a539e26261cbe280b9f48311663ce655.tar.xz |
PCI: iproc: Add 500ms delay during device shutdown
During soft reset (e.g., "reboot" from Linux) on some iProc-based SOCs, the
LCPLL clock and PERST both go off simultaneously. This seems in accordance
with the PCIe Card Electromechanical spec, r2.0, sec 2.2.3, which says the
clock goes inactive after PERST# goes active, but doesn't specify how long
the clock should be valid after PERST#.
However, we have observed that with the iProc Stingray, some Intel NVMe
endpoints, e.g., the P3700 400GB series, are not detected correctly upon
the next boot sequence unless the clock remains valid for some time after
PERST# is asserted.
Delay 500ms after asserting PERST# before performing a reboot. The 500ms
is experimentally determined.
Signed-off-by: Oza Pawandeep <oza.oza@broadcom.com>
[bhelgaas: changelog, add spec reference, fold in iproc_pcie_shutdown()
export from Arnd Bergmann <arnd@arndb.de>]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Diffstat (limited to 'drivers/pci/host/pcie-iproc.h')
-rw-r--r-- | drivers/pci/host/pcie-iproc.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/pci/host/pcie-iproc.h b/drivers/pci/host/pcie-iproc.h index 0bbe2ea44f3e..a6b55cec9a66 100644 --- a/drivers/pci/host/pcie-iproc.h +++ b/drivers/pci/host/pcie-iproc.h @@ -110,6 +110,7 @@ struct iproc_pcie { int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res); int iproc_pcie_remove(struct iproc_pcie *pcie); +int iproc_pcie_shutdown(struct iproc_pcie *pcie); #ifdef CONFIG_PCIE_IPROC_MSI int iproc_msi_init(struct iproc_pcie *pcie, struct device_node *node); |