Hi Bjorn,
On 2017/8/29 2:33, Bjorn Helgaas wrote:
On Mon, Aug 28, 2017 at 10:22:24AM +0800, Shawn Lin wrote:
Hi Bjorn,
On 2017/8/26 5:38, Bjorn Helgaas wrote:
On Wed, Aug 23, 2017 at 03:01:13PM +0800, Shawn Lin wrote:
...
I applied these to pci/host-rockchip except for these:
PCI: rockchip: fix system hang up if activating CONFIG_DEBUG_SHIRQ
PCI: rockchip: fix missing phy manipulation for legacy phy
I'm not really happy with the devm/clk_prepare_enable situation, so
I'm waiting to see if a better solution emerges.
I went ahead and applied the tweaks I proposed to the earlier "PCI:
rockchip: Add per-lane PHY support" and "PCI: rockchip: Idle inactive
PHY(s)" patches. I *think* those make the "fix missing phy
manipulation for legacy phy" patch unnecessary.
But please take a look and make sure. If I went the wrong direction,
I'll gladly back it out.
I tested both of legacy and per-lane PHY mode, and it works fine.
But just a nit:
with legacy PHY, we could avoid to print the following message
which is confusing as for legacy PHY mode, we couldn't idle
any inactive lanes.
[ 0.655192] rockchip-pcie f8000000.pcie: idling lane 1
[ 0.655696] rockchip-pcie f8000000.pcie: idling lane 2
[ 0.656194] rockchip-pcie f8000000.pcie: idling lane 3
So I think we could return 0xf for legacy PHY mode like this:
static u8 rockchip_pcie_lane_map(struct rockchip_pcie *rockchip)
u8 map;
if (rockchip->legacy_phy)
- return BIT(0);
+ return GENMASK(MAX_LANE_NUM - 1, 0);
When we're using legacy PHY mode, this changes lanes_map from 0x1 to
0xf. That means we won't print the "idling lane 1" message. It
*also* means we won't call phy_power_off() for lanes 1-3. Is that the
correct behavior? Does the legacy PHY mode actually use all 4 PHYs?
Yes, it's the correct behaviour. The 4 PHYs is abstraction of 4 lanes
for per-lane PHY mode, but for legacy PHY mode, PHY represents a single
component managing 4 lanes together. So no matter how many lanes are
used, we couldn't call phy_power_off for legacy PHY mode until we really
want to power off the PHY. That is why we need to recontruct the pcie
and phy driver to migrate to per-lane PHY mode as we could treat each
lane as a phy object and let phy driver do idling work in the
phy_power_off callback instead of power-off work if ref count isn't
decreased to zero.
Also I think the key point here is that for legacy PHY mode, only
phys[0] is vaild, so there is no difference if we call phy_power_off for
phys[1..3] as you did, because PHY API will check the phy object and
won't do anything if seeing invalid/NULL phy object. So changing
lanes_map from 0x1 to 0xf is only silent the "idling lane x" log.
