Include the header with prototype of owl_sps_set_pg to fix:
drivers/soc/actions/owl-sps-helper.c:16:5: warning: no previous prototype for 'owl_sps_set_pg' [-Wmissing-prototypes]
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
This commit adds DMA controller present on Actions S700, it differs from
S900 in terms of number of dma channels and requests.
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
After commit 7cdf8446ed ("arm64: dts: actions: Add pinctrl node for
Actions Semi S700") following error has been observed while booting
Linux on Cubieboard7-lite(based on S700 SoC).
[ 0.257415] pinctrl-s700 e01b0000.pinctrl: can't request region for
resource [mem 0xe01b0000-0xe01b0fff]
[ 0.266902] pinctrl-s700: probe of e01b0000.pinctrl failed with error -16
This is due to the fact that memory range for "sps" power domain controller
clashes with pinctrl.
One way to fix it, is to limit pinctrl address range which is safe
to do as current pinctrl driver uses address range only up to 0x100.
This commit limits the pinctrl address range to 0x100 so that it doesn't
conflict with sps range.
Fixes: 7cdf8446ed ("arm64: dts: actions: Add pinctrl node for Actions
Semi S700")
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Suggested-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
GPIO_ACTIVE_x flags are not correct in the context of interrupt flags.
These are simple defines so they could be used in DTS but they will not
have the same meaning:
1. GPIO_ACTIVE_HIGH = 0 = IRQ_TYPE_NONE
2. GPIO_ACTIVE_LOW = 1 = IRQ_TYPE_EDGE_RISING
Correct the interrupt flags, assuming the author of the code wanted same
logical behavior behind the name "ACTIVE_xxx", this is:
ACTIVE_LOW => IRQ_TYPE_LEVEL_LOW
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-By: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Add devicetree bindings for i.MX6 based phyCORE-i.MX6, phyBOARD-Mira and
phyFLEX-i.MX6.
Signed-off-by: Stefan Riedmueller <s.riedmueller@phytec.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Add devicetree bindings for i.MX6 UL/ULL based phyCORE-i.MX6 UL/ULL and
phyBOARD-Segin.
Signed-off-by: Stefan Riedmueller <s.riedmueller@phytec.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
As i.MX21 support has been removed, get rid of its clock driver too.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
mx35_clocks_init() has been used to register clocks on i.MX35
non-devicetree platforms.
Now that i.MX is a devicetree-only platform, it is safe to
remove mx35_clocks_init() as there are no more users.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
mx31_clocks_init() has been used to register clocks on i.MX31
non-devicetree platforms.
Now that i.MX is a devicetree-only platform, it is safe to
remove mx31_clocks_init() as there are no more users.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
mx27_clocks_init() has been used to register clocks on i.MX27
non-devicetree platforms.
Now that i.MX is a devicetree-only platform, it is safe to
remove mx27_clocks_init() as there are no more users.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Most of the definitions for peripheral base addresses, interrupt and
DMA information is no longer used, so get rid of them.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Now that imx35 has been converted to a devicetree-only platform,
retrieve the IIM base address from devicetree.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Now that imx31 and imx35 has been converted to a devicetree-only platform,
retrieve the AVIC base address from devicetree.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Now that imx31 and imx35 has been converted to a devicetree-only platform,
retrieve the CCM base address from devicetree.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Now that imx31 has been converted to a devicetree-only platform,
retrieve the IIM base address from devicetree.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Now that imx27 has been converted to a devicetree-only platform,
retrieve the CCM base address from devicetree.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Now that imx27 has been converted to a devicetree-only platform,
retrieve the SYSCTRL base address from devicetree.
To keep devicetree compatibilty the SYSCTRL base address will be
retrieved from the CCM base address plus an 0x800 offset.
This is not a problem as the imx27.dtsi describes the CCM register
range as 0x1000.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Since commit 9495b7e92f ("driver core: platform: Initialize dma_parms
for platform devices") driver core handles allocation of the dma_parms
structure for platform device, so there is no need to manually allocate
nor free it.
Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Enable the kernel modules for the board management controller "sl28cpld"
which is used on the SMARC-sAL28 board.
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
This commit adds support for Enhanced TX MPWQE feature in the regular
(SKB) data path. A MPWQE (multi-packet work queue element) can serve
multiple packets, reducing the PCI bandwidth on control traffic.
Two new stats (tx*_mpwqe_blks and tx*_mpwqe_pkts) are added. The feature
is on by default and controlled by the skb_tx_mpwqe private flag.
In a MPWQE, eseg is shared among all packets, so eseg-based offloads
(IPSEC, GENEVE, checksum) run on a separate eseg that is compared to the
eseg of the current MPWQE session to decide if the new packet can be
added to the same session.
MPWQE is not compatible with certain offloads and features, such as TLS
offload, TSO, nonlinear SKBs. If such incompatible features are in use,
the driver gracefully falls back to non-MPWQE.
This change has no performance impact in TCP single stream test and
XDP_TX single stream test.
UDP pktgen, 64-byte packets, single stream, MPWQE off:
Packet rate: 16.96 Mpps (±0.12 Mpps) -> 17.01 Mpps (±0.20 Mpps)
Instructions per packet: 421 -> 429
Cycles per packet: 156 -> 161
Instructions per cycle: 2.70 -> 2.67
UDP pktgen, 64-byte packets, single stream, MPWQE on:
Packet rate: 16.96 Mpps (±0.12 Mpps) -> 20.94 Mpps (±0.33 Mpps)
Instructions per packet: 421 -> 329
Cycles per packet: 156 -> 123
Instructions per cycle: 2.70 -> 2.67
Enabling MPWQE can reduce PCI bandwidth:
PCI Gen2, pktgen at fixed rate of 36864000 pps on 24 CPU cores:
Inbound PCI utilization with MPWQE off: 80.3%
Inbound PCI utilization with MPWQE on: 59.0%
PCI Gen3, pktgen at fixed rate of 56064000 pps on 24 CPU cores:
Inbound PCI utilization with MPWQE off: 65.4%
Inbound PCI utilization with MPWQE on: 49.3%
Enabling MPWQE can also reduce CPU load, increasing the packet rate in
case of CPU bottleneck:
PCI Gen2, pktgen at full rate on 24 CPU cores:
Packet rate with MPWQE off: 37.5 Mpps
Packet rate with MPWQE on: 49.0 Mpps
PCI Gen3, pktgen at full rate on 24 CPU cores:
Packet rate with MPWQE off: 57.0 Mpps
Packet rate with MPWQE on: 66.8 Mpps
Burst size in all pktgen tests is 32.
CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (x86_64)
NIC: Mellanox ConnectX-6 Dx
GCC 10.2.0
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
mlx5e_txwqe_complete performs some actions that can be taken to separate
functions:
1. Update the flags needed for hardware timestamping.
2. Stop the TX queue if it's full.
Take these actions into separate functions to be reused by the MPWQE
code in the following commit and to maintain clear responsibilities of
functions.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
As preparation for the upcoming TX MPWQE support for SKBs, rename struct
mlx5e_xdp_mpwqe to mlx5e_tx_mpwqe and move it above struct mlx5e_txqsq.
This structure will be reused in the regular SQ and in the regular TX
data path. Also rename mlx5e_xdp_xmit_data to mlx5e_xmit_data - it will
be used in the upcoming TX MPWQE flow.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
As preparation for the upcoming TX MPWQE for SKBs, create a function
(mlx5e_tx_mpwqe_is_full) to check whether an MPWQE session is full. This
function will be shared by MPWQE code for XDP and for SKBs. Defines are
renamed and moved to make them not XDP-specific.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
TX MPWQE support for SKBs is coming in one of the following patches, and
a single MPWQE can send multiple SKBs. This commit prepares the TX path
code to handle such cases:
1. An additional FIFO for SKBs is added, just like the FIFO for DMA
chunks.
2. struct mlx5e_tx_wqe_info will contain num_fifo_pkts. If a given WQE
contains only one packet, num_fifo_pkts will be zero, and the SKB will
be stored in mlx5e_tx_wqe_info, as usual. If num_fifo_pkts > 0, the SKB
pointer will be NULL, and the SKBs will be stored in the FIFO.
This change has no performance impact in TCP single stream test and
XDP_TX single stream test.
When compiled with a recent GCC, this change shows no visible
performance impact on UDP pktgen (burst 32) single stream test either:
Packet rate: 16.95 Mpps (±0.15 Mpps) -> 16.96 Mpps (±0.12 Mpps)
Instructions per packet: 429 -> 421
Cycles per packet: 160 -> 156
Instructions per cycle: 2.69 -> 2.70
CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (x86_64)
NIC: Mellanox ConnectX-6 Dx
GCC 10.2.0
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Before this patch, mlx5e_ktls_tx_handle_resync_dump_comp checked for
resync_dump_frag_page. It happened for all WQEs without an SKB,
including padding WQEs, and required a function call. Normally, padding
WQEs happen more often than TLS resyncs. Take this check out of the
function and put it to an inline function to save a call on all padding
WQEs.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
A constant for the number of DS in an empty WQE (i.e. a WQE without data
segments) is needed in multiple places (normal TX data path, MPWQE in
XDP), but currently we have a constant for XDP and an inline formula in
normal TX. This patch introduces a common constant.
Additionally, mlx5e_xdp_mpwqe_session_start is converted to use struct
assignment, because the code nearby is touched.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Use MLX5E_XDP_MPW_MAX_WQEBBS to reserve space for a MPWQE, because it's
actually the maximal size a MPWQE can take.
Reorganize the logic that checks when to close the MPWQE session:
1. Put all checks into a single function.
2. When inline is on, make only one comparison - if it's false, the less
strict one will also be false. The compiler probably optimized it out
anyway, but it's clearer to also reflect it in the code.
The MLX5E_XDP_INLINE_WQE_* defines are also changed to make the
calculations more correct from the logical point of view. Though
MLX5E_XDP_INLINE_WQE_MAX_DS_CNT used to be 16 and didn't change its
value, the calculation used to be DIV_ROUND_UP(max inline packet size,
MLX5_SEND_WQE_DS), and the numerator should have included sizeof(struct
mlx5_wqe_inline_seg).
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
A huge function mlx5e_sq_xmit was split into several to achieve multiple
goals:
1. Reuse the code in IPoIB.
2. Better intergrate with TLS, IPSEC, GENEVE and checksum offloads. Now
it's possible to reserve space in the WQ before running eseg-based
offloads, so:
2.1. It's not needed to copy cseg and eseg after mlx5e_fill_sq_frag_edge
anymore.
2.2. mlx5e_txqsq_get_next_pi will be used instead of the legacy
mlx5e_fill_sq_frag_edge for better code maintainability and reuse.
3. Prepare for the upcoming TX MPWQE for SKBs. It will intervene after
mlx5e_sq_calc_wqe_attr to check if it's possible to use MPWQE, and the
code flow will split into two paths: MPWQE and non-MPWQE.
Two high-level functions are provided to send packets:
* mlx5e_xmit is called by the networking stack, runs offloads and sends
the packet. In one of the following patches, MPWQE support will be added
to this flow.
* mlx5e_sq_xmit_simple is called by the TLS offload, runs only the
checksum offload and sends the packet.
This change has no performance impact in TCP single stream test and
XDP_TX single stream test.
When compiled with a recent GCC, this change shows no visible
performance impact on UDP pktgen (burst 32) single stream test either:
Packet rate: 16.86 Mpps (±0.15 Mpps) -> 16.95 Mpps (±0.15 Mpps)
Instructions per packet: 434 -> 429
Cycles per packet: 158 -> 160
Instructions per cycle: 2.75 -> 2.69
CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (x86_64)
NIC: Mellanox ConnectX-6 Dx
GCC 10.2.0
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Move mlx5e_tx_wqe_inline_mode from en/txrx.h to en_tx.c as it's only
used there.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Struct assignment guarantees that all fields of the structure are
initialized (those that are not mentioned are zeroed). It makes code
mode robust and reduces chances for unpredictable behavior when one
forgets to reset some field and it holds an old value from previous
iterations of using the structure.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
As preparation for the next patch, don't increase ihs to calculate
ds_cnt and then decrease it, but rather calculate the intermediate value
temporarily. This code has the same amount of arithmetic operations, but
now allows to split out ds_cnt calculation, which will be performed in
the next patch.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Select the eLCDIF display controller and Raydium RM67191 panel drivers,
so that MIPI DSI can be functional by default on a imx8mq-evk board.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Using the native SPI chipselect on i.MX6 is known to be problematic.
Doing it on a imx6q-sabresd causes the SPI NOR probe to fail:
[ 5.388704] spi-nor spi0.0: unrecognized JEDEC id bytes: 00 00 00 00 00 00
Use the GPIO chipselect to avoid such problem.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Add an entry for imx6q-logicpd.dtb so that it can be built by default.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
It is standard practice to have a specific board compatible string, so
pass "logicpd,imx6q-logicpd".
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
dtschema for pca95xx expects GPIO hogs to end with 'hog' prefix. While
touching the hogs, fix indentation (spaces -> tabs).
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Build the kernel with `C=2`:
arch/powerpc/kvm/book3s_hv_nested.c:572:25: warning: symbol
'kvmhv_alloc_nested' was not declared. Should it be static?
arch/powerpc/kvm/book3s_64_mmu_radix.c:350:6: warning: symbol
'kvmppc_radix_set_pte_at' was not declared. Should it be static?
arch/powerpc/kvm/book3s_hv.c:3568:5: warning: symbol
'kvmhv_p9_guest_entry' was not declared. Should it be static?
arch/powerpc/kvm/book3s_hv_rm_xics.c:767:15: warning: symbol 'eoi_rc'
was not declared. Should it be static?
arch/powerpc/kvm/book3s_64_vio_hv.c:240:13: warning: symbol
'iommu_tce_kill_rm' was not declared. Should it be static?
arch/powerpc/kvm/book3s_64_vio.c:492:6: warning: symbol
'kvmppc_tce_iommu_do_map' was not declared. Should it be static?
arch/powerpc/kvm/book3s_pr.c:572:6: warning: symbol 'kvmppc_set_pvr_pr'
was not declared. Should it be static?
Those symbols are used only in the files that define them so make them
static to fix the warnings.
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The variable ret is being initialized with '-ENOMEM' that is meaningless.
So remove it.
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Fix to remove tailing spaces after value. If there is a space
after value, the bootconfig failed to remove it because it
applies strim() before replacing the delimiter with null.
For example,
foo = var # comment
was parsed as below.
foo="var "
but user will expect
foo="var"
This fixes it by applying strim() after removing the delimiter.
Link: https://lkml.kernel.org/r/160068149134.1088739.8868306567670058853.stgit@devnote2
Fixes: 76db5a27a8 ("bootconfig: Add Extra Boot Config support")
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The pin configuration for PMIC interrupt is already set by
imx8mn-evk.dtsi with exactly the same values.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
The Symphony board uses GPIO from expander as Ethernet PHY reset pin,
not the GPIO1_IO9.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
The i2c3 clock frequency and pin configuration are already set by
imx8mm-var-som.dtsi.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Fix a bug of breaking existing tree nodes by parsing the second
and subsequent braces. Since the bootconfig parser uses the
node.next field as a flag of current parent node, but this will
break the existing tree if the same key node is specified again
in the bootconfig.
For example, the following bootconfig should be foo.buz and bar.
foo
bar
foo { buz }
However, when parsing the brace "{", it breaks foo->bar link
by marking open-brace node. So the bootconfig unlinks bar
from the bootconfig internal tree.
This introduces a stack outside of the tree and record the
last open-brace on the stack instead of using node.next field.
Link: https://lkml.kernel.org/r/160068148267.1088739.8264704338030168660.stgit@devnote2
Fixes: 76db5a27a8 ("bootconfig: Add Extra Boot Config support")
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add the note about when to start the boot-time tracing.
This will be needed for the people who wants to trace
earlier boot sequence.
Link: https://lkml.kernel.org/r/159974156678.478751.10215894815285734481.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
