diff options
| author |   Marek Vasut <marek.vasut+renesas@gmail.com> | 2021-08-15 20:16:50 +0200 |
|---|---|---|
| committer |   Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2021-08-16 14:51:30 +0100 |
| commit | a115b1bd3af0c2963e72f6e47143724c59251be6 (patch) | |
| tree | 4dd2d26cad2210e9059fe38ad20ec9b08cfbcf49 /drivers/pci/controller/pcie-rcar.h | |
| parent | PCI: rcar: Fix runtime PM imbalance in rcar_pcie_ep_probe() (diff) | |
| download | wireguard-linux-a115b1bd3af0c2963e72f6e47143724c59251be6.tar.xz wireguard-linux-a115b1bd3af0c2963e72f6e47143724c59251be6.zip | |
PCI: rcar: Add L1 link state fix into data abort hook
When the link is in L1, hardware should return it to L0
automatically whenever a transaction targets a component on the
other end of the link (PCIe r5.0, sec 5.2).
The R-Car PCIe controller doesn't handle this transition correctly.
If the link is not in L0, an MMIO transaction targeting a downstream
device fails, and the controller reports an ARM imprecise external
abort.
Work around this by hooking the abort handler so the driver can
detect this situation and help the hardware complete the link state
transition.
When the R-Car controller receives a PM_ENTER_L1 DLLP from the
downstream component, it sets PMEL1RX bit in PMSR register, but then
the controller enters some sort of in-between state. A subsequent
MMIO transaction will fail, resulting in the external abort. The
abort handler detects this condition and completes the link state
transition by setting the L1IATN bit in PMCTLR and waiting for the
link state transition to complete.
Link: https://lore.kernel.org/r/20210815181650.132579-1-marek.vasut@gmail.com
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: linux-renesas-soc@vger.kernel.org
Diffstat (limited to 'drivers/pci/controller/pcie-rcar.h')
| -rw-r--r-- | drivers/pci/controller/pcie-rcar.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/pci/controller/pcie-rcar.h b/drivers/pci/controller/pcie-rcar.h index d4c698b5f821..9bb125db85c6 100644 --- a/drivers/pci/controller/pcie-rcar.h +++ b/drivers/pci/controller/pcie-rcar.h @@ -85,6 +85,13 @@ #define LTSMDIS BIT(31) #define MACCTLR_INIT_VAL (LTSMDIS | MACCTLR_NFTS_MASK) #define PMSR 0x01105c +#define L1FAEG BIT(31) +#define PMEL1RX BIT(23) +#define PMSTATE GENMASK(18, 16) +#define PMSTATE_L1 (3 << 16) +#define PMCTLR 0x011060 +#define L1IATN BIT(31) + #define MACS2R 0x011078 #define MACCGSPSETR 0x011084 #define SPCNGRSN BIT(31) |