Given the agreement on the edk2-devel regarding the fact that the
notion whether or not a 'platform has ACPI' is a universal one, move
the PlatformHasAcpi GUID to MdeModulePkg.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: "Zeng, Star" <star.zeng@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
To give platforms some room to decide which DTB is suitable and where
to load it from, load the DTB image indirectly via the new
DtPlatformDtbLoaderLib library class.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Introduce an implementation of the new DtPlatformDtbLoaderLib library
class that simply retrieves the first raw section of an FV file named
'gDtPlatformDefaultDtbFileGuid'.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
To abstract the way a platform reasons about which DTB is appropriate,
and the way it ultimately supplies the DTB image, introduce a new library
class to encapsulate this functionality.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Add the new DtPlatformDxe driver to EmbeddedPkg's .dsc file so that
we can build it outside the context of a platform.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
As a follow up to the changes proposed by Laszlo to make ACPI and DT
mutually exclusive on ArmVirtQemu, this patch proposes a DT platform
DXE driver that either installs the NULL protocol PlatformHasAcpiGuid,
or installs the FV embedded DTB binary as a configuration table under
the appropriate GUID, depending on a preference setting recorded as
a UEFI variable, and configurable via a HII screen.
The DTB binary can be embedded in the firmware image by adding the
following to the platform .fdf file:
FILE FREEFORM = 25462CDA-221F-47DF-AC1D-259CFAA4E326 {
SECTION RAW = SomePkg/path/to/foo.dtb
}
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
The presence of this GUID in the PPI database, and/or in the DXE protocol
database (as dictated by the platform's needs in these firmware phases)
implies that the platform provides the operating system with a Device
Tree-based hardware description. This is not necessarily exclusive with
other types of hardware description (for example, an ACPI-based one).
A platform PEIM and/or DXE driver is supposed to produce a single instance
of the PPI and/or protocol (with NULL contents), if appropriate. The
decision to produce the PPI and/or protocol is platform specific; for
example, in the DXE phase, it could depend on an HII checkbox / underlying
non-volatile UEFI variable.
In the DXE phase, the protocol is meant to be consumed by the platform
driver that
- owns the Device Tree description of the hardware, and
- is responsible for installing it as a system configuration table.
Said FDT-owner driver can wait for the protocol via DEPEX or protocol
notify.
Because this GUID is not standard, it is prefixed with EDKII / Edkii, as
seen elsewhere (for example in MdeModulePkg and SecurityPkg).
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Add the shorter-term library instance outlined in the previous patch to
EmbeddedPkg, so that we can imbue AcpiTableDxe with a protocol dependency
on EDKII_PLATFORM_HAS_ACPI_GUID.
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
The presence of this GUID in the PPI database, and/or in the DXE protocol
database (as dictated by the platform's needs in these firmware phases)
implies that the platform provides the operating system with an ACPI-based
hardware description. This is not necessarily exclusive with other types
of hardware description (for example, a Device Tree-based one).
A platform PEIM and/or DXE driver is supposed to produce a single instance
of the PPI and/or protocol (with NULL contents), if appropriate. The
decision to produce the PPI and/or protocol is platform specific; for
example, in the DXE phase, it could depend on an HII checkbox / underlying
non-volatile UEFI variable.
In the DXE phase, the protocol is meant to be depended-upon by
"MdeModulePkg/Universal/Acpi/AcpiTableDxe", indirectly:
* In the long term, interested platforms will establish this dependency by
hooking an (upcoming) NULL-class DepexLib instance into AcpiTableDxe in
their DSC files, pointing DepexLib's DEPEX through a FixedAtBuild PCD to
the GUID introduced here. (For the prerequisite BaseTools feature, refer
to <https://bugzilla.tianocore.org/show_bug.cgi?id=443>).
* In the short term, an interested platform may hook a private NULL-class
library instance (called e.g. "PlatformHasAcpiLib") into AcpiTableDxe.
Such a library instance would be a specialization of the above described
generic DepexLib, with the DEPEX open-coded on the GUID introduced here.
Either way, the platform makes EFI_ACPI_TABLE_PROTOCOL and (if enabled)
EFI_ACPI_SDT_PROTOCOL dependent on the platform's dynamic decision to
produce or not to produce a NULL protocol instance with this GUID.
In turn, other (platform and universal) DXE drivers that produce ACPI
tables will wait for EFI_ACPI_TABLE_PROTOCOL / EFI_ACPI_SDT_PROTOCOL, via
DEPEX, protocol notify, or a simple gBS->LocateProtocol() in a "late
enough" callback (such as Ready To Boot).
Because this GUID is not standard, it is prefixed with EDKII / Edkii, as
seen elsewhere in MdeModulePkg and SecurityPkg. In addition, an effort is
made to avoid the phrase "AcpiPlatform", as that belongs to drivers /
libraries that produce platform specific ACPI content (as opposed to
deciding whether the entire firmware will have access to
EFI_ACPI_TABLE_PROTOCOL, or any similar facilities in the PEI phase).
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
The recently introduced memory protection features inadvertently broke
the boot on all PrePi platforms, because the changes to explicitly use
EfiBootServicesCode for loading the DxeCore PE/COFF image need to be
applied in a different way for PrePi. So add a simple helper function
that sets the type of an allocation to EfiBootServicesCode, and invoke
it to allocate the space for DxeCore.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Michael Zimmermann <sigmaepsilon92@gmail.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
LzmaCustomDecompressLib and PeiDxeDebugLibReportStatusCode were copied
from IntelFrameworkModulePkg to MdeModulePkg, but the originals were
kept for compatibility.
Since the libraries are identical, move EmbeddedPkg to use the
MdeModulePkg versions instead.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
When booting the kernel via Fastboot, invoke the kernel image directly
rather than passing it to the LinuxLoader app. This requires the kernel
image to be built with UEFI stub support.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Ryan Harkin <ryan.harkin@linaro.org>
Make use of DMA to transfer multiple blocks at one time. It could
improve the performance on MMC/SD driver.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Add the interface to change the bus width and speed.
By default, MMC is initialized with 1-bit mode and less than 400KHz bus
clock. It causes MMC working inefficiently.
Set I/O bus width on both MMC controller and EXTCSD. Otherwise, it may
cause unmatched failure case. And support more timing mode, high speed,
HS200 & HS400 mode.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Add new protocol methods to change the bus width, speed and check
for multiblock support.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Split off protocol changes from implementation changes.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Declare fields in ECSD structure. And drop the original 128 words
arrary.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Since ECSD also describes the information of card, move it into
structure CardInfo.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
According to eMMC spec, OCR.PowerUp bit is also busy bit. If the busy
bit is '0', CMD1 should be sent and OCR should be fetched again. And add
a timeout counter on the repeated steps.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Define DISABLE_NEW_DEPRECATED_INTERFACES on the compiler command line by
default, to prevent deprecated interfaces from being used in core EDK2
code.
Bug: https://bugzilla.tianocore.org/show_bug.cgi?id=164
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Get rid of calls to unsafe string functions. These are deprecated and may
be removed in the future.
Note that this also fixes an existing issue in the code, where the buffer
may be overrun by one character when en == mLogRemainChar, in which case
the NUL terminator ends up after the end of the buffer.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Get rid of calls to unsafe string functions. These are deprecated and may
be removed in the future.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Get rid of calls to unsafe string functions. These are deprecated and may
be removed in the future.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Get rid of calls to unsafe string functions. These are deprecated and may
be removed in the future.
Note that this also addresses a latent potential issue in HandleDownload(),
where NumBytesString[] (which comes from the wire) is assumed to contain a
string representation of a number with all the significant digits in the
first 8 bytes, which is not guaranteed by the protocol.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
The result of PcdGet64() can only be cast to VOID* on 64-bit platforms,
so add an intermediate UINTN cast to make this code build again on 32 bit.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Add modules that live under EmbeddedPkg but were missing from the
[Components] section of the package .dsc file
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Remove this unused version: all existing platforms use the one under
ArmPlatformPkg instead.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
The fastboot TCP connection setup routine retrieves a hostname from a
UEFI variable 'hostname' that is scoped under a GUID gEfiHostnameVariableGuid
whose definition is missing from the code. Since the hostname is only printed
and then discarded, let's just drop the whole thing.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
The various ArmLib flavors are identical in practice, and a new
ArmBaseLib has been introduced that can replace all of them. So replace
all occurrences with ArmBaseLib.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
This library is only used by the various PrePi implementations, all of
which are of type SEC. So make this library SEC as well. This may affect
the build options used by the platform.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
ACPI 6.0 added a processor efficiency field and 3 reserved bytes at the
end of the GICC structure so add a new macro to initialise the new
field.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Conform to the specification for GetStatus(), which states that "if
there are no transmit buffers to recycle and TxBuf is not NULL, *TxBuf
will be set to NULL".
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Add a PCD to allow the platform to mask in/out specific features of
the LAN9118 device advertised during auto-negotiation.
For example, the Juno ARM Development Platform doesn't support full
duplex mode. This PCD will allow the platform developer to prevent the
full duplex modes from being advertised.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
[ardb: change default feature mask so that full duplex is disabled]
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Leif Lindholm <leif.lindholm@linaro.org>
Now that the LAN9118-specific MMIO accessors provide the required
delays, remove the redundant stalls.
Stalls in delay loops are kept, as these give time for work to happen
beyond synchronisation of the device register file.
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ryan Harkin <ryan.harkin@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Migrate the existing code to use the new LAN9118 MMIO wrappers, ensuring
that timing requirements are respected.
The newly redundant stalls will be removed in a subsequent patch.
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ryan Harkin <ryan.harkin@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
As described in the LAN9118 datasheet, delays are necessary after some
reads and writes in order to ensure subsequent reads do not see stale
data.
This patch adds helpers to provide these delays automatically, by
performing dummy reads of the BYTE_TEST register (as recommended in the
LAN9118 datasheet). This approach allows the device register file itself
to provide the required delay, avoiding issues with early write
acknowledgement, or re-ordering of MMIO accesses aganist other
instructions (e.g. the delay loop).
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ryan Harkin <ryan.harkin@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Commit a4626006bb ("EmbeddedPkg/Lan9118Dxe: use MemoryFence")
replaced some stalls with memory fences, on the presumption that these
were erroneously being used to order memory accesses. However, this was
not the case.
LAN9118 devices require a timing delay between state-changing
reads/writes and subsequent reads, as updates to the register file are
asynchronous and the effects of state-changes are not immediately
visible to subsequent reads.
This delay cannot be ensured through the use of memory barriers, which
only enforce observable ordering, and not timing. Thus, converting these
stalls to memory fences was erroneous, and may result in stale values
being read.
This reverts commit a4626006bb.
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ryan Harkin <ryan.harkin@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
The Reserved field in the SBSA Generic Watchdog Structure is 1 byte in
length. Refer Table 5-123 in the ACPI 5.1 Specification Errata A.
The EFI_ACPI_5_1_SBSA_GENERIC_WATCHDOG_STRUCTURE_INIT() helper
macro was initializing this field as EFI_ACPI_RESERVED_WORD instead of
EFI_ACPI_RESERVED_BYTE.
Although this does not cause any functional issue; it does not comply
with the specification.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Evan Lloyd <evan.lloyd@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
EmbeddedGpio only supports one gpio controller in one platform. Now
create PLATFORM_GPIO_CONTROLLER to support multiple gpio controllers
in one platform.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Since there's percentage calcution, multiply on 32bit variable
will cause overflow. So fix the variables as 64bit.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
The variable TimeOut is actually a retry, not a timeout, so I renamed
the variable accordingly.
This patch makes no functional change.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
This patch makes a few minor DEBUG output changes:
- Fix typo in DEBUG output: Negociation->Negotiation
- Change DEBUG occurrences of "Lan9118" to "LAN9118" to make grepping
the log output easier.
- Change the warning that auto-negotiation is not supported when
AutoNegotiate() returns an error.
The function already reports if the feature is supported or not and
can also return an error for other reasons.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Add a PCD for the link negotiation timeout so the platform can over-ride
the default value.
The code previously did 2000 iterations of the loop with a 2us stall, so
the code has been changed subtly to set the number of iterations equal
to the PCD value divided by the stall time.
Since the stall time has not changed, the default PCD value is set at
4000 so the original behaviour is not changed.
The problems were discovered when the ARM Juno Development Platform used
the "EFI Network" option with then LAN9118 driver. It fails to boot the
first time and so the board drops back to Shell again:
Warning: LAN9118 Driver in stopped state
Link timeout in auto-negotiation.
Lan9118: Auto Negociation not supported.
EhcExecTransfer: transfer failed with 2
EhcControlTransfer: error - Device Error, transfer - 2
Buffer: EFI Hard Drive
Booting EFI Misc Device
Booting EFI Misc Device 1
Booting EFI Hard Drive
Booting EFI Network
Warning: LAN9118 Driver not initialized
Link timeout in auto-negotiation.
Lan9118: Auto Negociation not supported.
Booting EFI Internal Shell
Exiting Shell drops the user back to the Intel BDS UI. Selecting
"Continue" then succeeds in booting from the EFI Network:
Booting EFI Misc Device
Booting EFI Misc Device 1
Booting EFI Hard Drive
Booting EFI Network
..MnpFreeTxBuf: Duplicated recycle report from SNP.
MnpFreeTxBuf: Duplicated recycle report from SNP.
[snip repeated errors]
Discussion on the edk2-devel mailing list [1] prompted Laszlo Ersek to
suggest the time taken for the NIC to negotiate was causing a problem.
He suggested the solution contained in this patch to provide a PCD
configurable by the platform.
The default PCD value does not work for Juno. Setting the PCD to a
larger value works for Juno R0, R1 and R2.
[1] http://article.gmane.org/gmane.comp.bios.edk2.devel/7341
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
When reviewing my LAN9118 driver PCD patch [1], Ard Biesheuvel noted
that most calls to gBS->Stall() in this driver seem to be used to
prevent timing issues between the device updating data and the host
reading the values. And that replacing most of these calls with a
MemoryFence() would be more robust.
The only exceptions are the stalls that are enclosed inside retry loops:
- in the AutoNegotiate() function.
This stall is waiting for the link to negotiate, which may require
stalling until it is ready.
- in the Lan9118Initialize() function.
These two stalls are waiting for devices and time out after a number
of retries.
- in the SoftReset() function.
This stall is inside a loop where the comment states:
"If time taken exceeds 100us, then there was an error condition"
In these instances, I kept the stall, but also added a MemoryFence().
[1] http://article.gmane.org/gmane.comp.bios.edk2.devel/7389
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Ard Biesheuvel
Laszlo Ersek
Leif Lindholm
Haojian Zhuang
Gary Lin
Ruiyu Ni
Graeme Gregory
Michael Brown
Ryan Harkin
Mark Rutland
Heyi Guo
Sami Mujawar
Leendert van Doorn
Leo Duran