On 10/27/17 05:23, Zeng, Star wrote: > Reviewed-by: Star Zeng <[email protected]> after the minor typo " isse " is > fixed to " issue ".
Yup, I noticed that too late. I'll fix it when I push the patch (still waiting for test results from Aleksei as well). Thanks! Laszlo > > Thanks, > Star > -----Original Message----- > From: Laszlo Ersek [mailto:[email protected]] > Sent: Thursday, October 26, 2017 11:48 PM > To: edk2-devel-01 <[email protected]> > Cc: Aleksei Kovura <[email protected]>; Ard Biesheuvel > <[email protected]>; Dann Frazier <[email protected]>; Dong, Eric > <[email protected]>; Zeng, Star <[email protected]> > Subject: [PATCH] MdeModulePkg/AtaAtapiPassThru: disable only BM-DMA at > ExitBootServices() > > Clearing I/O port decoding in the PCI command register at > ExitBootServices() breaks IDE boot in Windows, on QEMU's "pc" (i440fx) > machine type. (AHCI boot on "q35" is unaffected.) Windows seems repeatedly > stuck, apparently waiting for a timeout of sorts. > > This is arguably a Windows bug; a native OS driver should not expect the > firmware to leave the PCI command register in any particular state. > > Strictly speaking, we only need to disable BM-DMA at ExitBootServices(), in > order to abort pending transfers to/from RAM, which is soon to be owned by > the OS. BM-DMA is also the only bit that's explicitly named by the UEFI > Driver Writers' Guide, for clearing at ExitBootServices(). > > I've verified that clearing only BM-DMA fixes the isse (boot time) on i440fx, > and does not regress q35/AHCI. > > Cc: Aleksei Kovura <[email protected]> > Cc: Ard Biesheuvel <[email protected]> > Cc: Dann Frazier <[email protected]> > Cc: Eric Dong <[email protected]> > Cc: Star Zeng <[email protected]> > Reported-by: Aleksei Kovura <[email protected]> > Reported-by: Dann Frazier <[email protected]> > Reported-by: https://launchpad.net/~cjkrupp > Bisected-by: Dann Frazier <[email protected]> > Bisected-by: https://launchpad.net/~cjkrupp > Suggested-by: Ard Biesheuvel <[email protected]> > Suggested-by: Star Zeng <[email protected]> > Ref: https://bugs.launchpad.net/ubuntu/+source/edk2/+bug/1725560 > Fixes: 6fb8ddd36bde45614b0a069528cdc97077835a74 > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Laszlo Ersek <[email protected]> > --- > > Notes: > Repo: https://github.com/lersek/edk2.git > Branch: ata_disable_only_bmdma > > MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.h | 3 +-- > MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.c | 5 ++--- > 2 files changed, 3 insertions(+), 5 deletions(-) > > diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.h > b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.h > index 8d6eac706c0b..92c5bf2001cd 100644 > --- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.h > +++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.h > @@ -123,8 +123,7 @@ typedef struct { > LIST_ENTRY NonBlockingTaskList; > > // > - // For disabling the device (especially Bus Master DMA) at > - // ExitBootServices(). > + // For disabling Bus Master DMA on the device at ExitBootServices(). > // > EFI_EVENT ExitBootEvent; > } ATA_ATAPI_PASS_THRU_INSTANCE; > diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.c > b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.c > index 09064dda18b7..e10e0d4e65f6 100644 > --- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.c > +++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.c > @@ -480,8 +480,7 @@ InitializeAtaAtapiPassThru ( } > > /** > - Disable the device (especially Bus Master DMA) when exiting the boot > - services. > + Disable Bus Master DMA on the device when exiting the boot services. > > @param[in] Event Event for which this notification function is being > called. > @@ -506,7 +505,7 @@ AtaPassThruExitBootServices ( > PciIo->Attributes ( > PciIo, > EfiPciIoAttributeOperationDisable, > - Instance->EnabledPciAttributes, > + Instance->EnabledPciAttributes & > + EFI_PCI_IO_ATTRIBUTE_BUS_MASTER, > NULL > ); > } > -- > 2.14.1.3.gb7cf6e02401b > _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
