> Am 10.01.2019 um 09:02 schrieb AKASHI Takahiro <takahiro.aka...@linaro.org>: > >> On Thu, Jan 10, 2019 at 08:30:13AM +0100, Alexander Graf wrote: >> >> >>> On 10.01.19 08:26, AKASHI Takahiro wrote: >>> Alex, >>> >>>> On Thu, Jan 10, 2019 at 07:21:12AM +0100, Alexander Graf wrote: >>>> >>>> >>>>> On 10.01.19 03:13, AKASHI Takahiro wrote: >>>>> Alex, >>>>> >>>>>> On Wed, Jan 09, 2019 at 10:06:16AM +0100, Alexander Graf wrote: >>>>>> >>>>>> >>>>>>> On 13.12.18 08:58, AKASHI Takahiro wrote: >>>>>>> Heinrich, >>>>>>> >>>>>>>> On Tue, Dec 11, 2018 at 08:55:41PM +0100, Heinrich Schuchardt wrote: >>>>>>>>> On 11/15/18 5:58 AM, AKASHI Takahiro wrote: >>>>>>>>> Currently, efi_init_obj_list() scan disk devices only once, and never >>>>>>>>> change a list of efi disk devices. This will possibly result in >>>>>>>>> failing >>>>>>>>> to find a removable storage which may be added later on. See [1]. >>>>>>>>> >>>>>>>>> In this patch, called is efi_disk_update() which is responsible for >>>>>>>>> re-scanning UCLASS_BLK devices and removing/adding efi disks if >>>>>>>>> necessary. >>>>>>>>> >>>>>>>>> For example, >>>>>>>>> >>>>>>>>> => efishell devices >>>>>>>>> Scanning disk pci_mmc.blk... >>>>>>>>> Found 3 disks >>>>>>>>> Device Name >>>>>>>>> ============================================ >>>>>>>>> /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b) >>>>>>>>> /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/SD(0)/SD(0) >>>>>>>>> /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/SD(0)/SD(0)/HD(2,MBR,0x086246ba,0x40800,0x3f800) >>>>>>>>> => usb start >>>>>>>>> starting USB... >>>>>>>>> USB0: USB EHCI 1.00 >>>>>>>>> scanning bus 0 for devices... 3 USB Device(s) found >>>>>>>>> scanning usb for storage devices... 1 Storage Device(s) found >>>>>>>>> => efishell devices >>>>>>>>> Scanning disk usb_mass_storage.lun0... >>>>>>>>> Device Name >>>>>>>>> ============================================ >>>>>>>>> /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b) >>>>>>>>> /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/SD(0)/SD(0) >>>>>>>>> /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/SD(0)/SD(0)/HD(2,MBR,0x086246ba,0x40800,0x3f800) >>>>>>>>> /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/USBClass(0,0,9,0,1)/USBClass(46f4,1,0,0,0)/HD(1,0x01,0,0x40,0x14fe4c) >>>>>>>>> >>>>>>>>> Without this patch, the last device, USB mass storage, won't show up. >>>>>>>>> >>>>>>>>> [1] https://lists.denx.de/pipermail/u-boot/2018-October/345307.html >>>>>>>>> >>>>>>>>> Signed-off-by: AKASHI Takahiro <takahiro.aka...@linaro.org> >>>>>>>> >>>>>>>> Why should we try to fix something in the EFI subsystems that goes >>>>>>>> wrong >>>>>>>> in the handling of device enumeration. >>>>>>> >>>>>>> No. >>>>>>> This is a natural result from how efi disks are currently implemented >>>>>>> on u-boot. >>>>>>> Do you want to totally re-write/re-implement efi disks? >>>>>> >>>>>> Could we just make this event based for now? Call a hook from the >>>>>> storage dm subsystem when a new u-boot block device gets created to >>>>>> issue a sync of that in the efi subsystem? >>>>> >>>>> If I correctly understand you, your suggestion here corresponds >>>>> with my proposal#3 in [1] while my current approach is #2. >>>>> >>>>> [1] https://lists.denx.de/pipermail/u-boot/2018-October/345307.html >>>> >>>> Yes, I think so. >>>> >>>>> So we will call, say, efi_disk_create(struct udevice *) in >>>>> blk_create_device() and efi_dsik_delete() in blk_unbind_all(). >>>> >>>> I would prefer if we didn't call them directly, but through an event >>>> mechanism. So the efi_disk subsystem registers an event with the dm >>>> block subsystem and that will just call all events when block devices >>>> get created which will automatically also include the efi disk creation >>>> callback. Same for reverse. >>> >>> Do you mean efi event by "event?" >>> (I don't think there is any generic event interface on DM side.) >>> >>> Whatever an "event" is or whether we call efi_disk_create() directly >>> or indirectly via an event, there is one (big?) issue in this approach >>> (while I've almost finished prototyping): >>> >>> We cannot call efi_disk_create() within blk_create_device() because >>> some data fields of struct blk_desc, which are to be used by efi disk, >>> are initialized *after* blk_create_device() in driver side. >>> >>> So we need to add a hook at/after every occurrence of blk_create_device() >>> on driver side. For example, >>> >>> === drivers/scsi/scsi.c === >>> int do_scsi_scan_one(struct udevice *dev, int id, int lun, bool verbose) >>> { >>> ... >>> ret = blk_create_devicef(dev, "scsi_blk", str, IF_TYPE_SCSI, -1, >>> bd.blksz, bd.lba, &bdev); >>> ... >>> bdesc = dev_get_uclass_platdata(bdev); >>> bdesc->target = id; >>> bdesc->lun = lun; >>> ... >>> >>> /* >>> * We need have efi_disk_create() called here because bdesc->target >>> * and lun will be used by dp helpers in efi_disk_add_dev(). >>> */ >>> efi_disk_create(bdev); >>> } >>> >>> int scsi_scan_dev(struct udevice *dev, bool verbose) >>> { >>> for (i = 0; i < uc_plat->max_id; i++) >>> for (lun = 0; lun < uc_plat->max_lun; lun++) >>> do_scsi_scan_one(dev, i, lun, verbose); >>> ... >>> } >>> >>> int scsi_scan(bool verbose) >>> { >>> ret = uclass_get(UCLASS_SCSI, &uc); >>> ... >>> uclass_foreach_dev(dev, uc) >>> ret = scsi_scan_dev(dev, verbose); >>> ... >>> } >>> === === >>> >>> Since scsn_scan() can be directly called by "scsi rescan" command, >>> There seems to be no generic hook, or event, available in order to >>> call efi_disk_create(). >>> >>> Do I miss anything? >> >> Could the event handler that gets called from somewhere around >> blk_create_device() just put it into an efi internal "todo list" which >> we then process using an efi event? >> >> EFI events will only get triggered on the next entry to efi land, so by >> then we should be safe. > > I think I now understand your suggestion; we are going to invent > a specialized event-queuing mechanism so that we can take any actions > later at appropriate time (probably in efi_init_obj_list()?).
Uh, not sure I follow. There would be 2 events. One from the u-boot block layer to the efi_loader disk layer. That event handler creates a new efi event (like a timer w/ timeout=0). This new event's handler can then create the actual efi block device. > > But if so, it's not much different from my current approach where > a list of efi disks are updated in efi_init_obj_list() :) The main difference is that disk logic stays in the disc code scope :). Alex > > -Takahiro Akashi > > >> >> Alex _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
