May I know the details what problems it causes in some cases? Thanks, Ye Ting
-----Original Message----- From: Andrei Borzenkov [mailto:[email protected]] Sent: Wednesday, October 14, 2015 1:58 PM To: Ye, Ting; Laszlo Ersek; [email protected]; [email protected] Cc: [email protected]; edk2-devel-01; [email protected]; [email protected]; Mark Salter Subject: Re: [edk2] [grub PATCH] efinet: disable MNP background polling 14.10.2015 08:19, Ye, Ting пишет: > Hi all, > > If I understand the issue correctly, I don't quite agree that UEFI spec is > imprecise about SNP constraints described as following. > The "constraint" described here is that the grub should use attribute > "EXCLUSIVE" to open SNP protocol to gain exclusive access. This usage is > clearly described in page 184, chapter 6.3 EFI_BOOT_SERVICES.OpenProtocol(). > > EXCLUSIVE Used by applications to gain exclusive access to a > protocol interface. > If any drivers have the protocol interface opened with > an attribute of BY_DRIVER, > then an attempt will be made to remove them by calling > the driver's Stop() function. > > The grub code should not assume that the SNP is not occupied by other > drivers, instead, it should use EXCLUSIVE to open SNP protocol, or to be more > precise, use OpenProtocolInformation() to check whether SNP is already opened > by other driver, then decide whether need to use EXCLUSIVE to disconnect the > other drivers. This is the typical usage for all UEFI protocol, not > particular constraints to SNP protocol. > That is exactly what grub currently does - it opens SNP exclusively. Apparently it is causing problems in some cases. _______________________________________________ Grub-devel mailing list [email protected] https://lists.gnu.org/mailman/listinfo/grub-devel
