On Thu, Jan 10, 2019 at 09:15:36AM +0100, Alexander Graf wrote: > > > > 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.
This is a to-be-invented "specialized event-queuing mechanism" in my language :) as we cannot use efi_create/signal_event() before initializing EFI environment. This event will be expected to be 'signal'ed at every creation/deletion of UCLASS_BLK device. Right? > That event handler creates a new efi event (like a timer w/ timeout=0). But when is this event handler fired? I think the only possible timing is at efi_init_obj_list(). > This new event's handler can then create the actual efi block device. I assume that this event handler is fired immediately after efi_signal_event() with timeout=0. If so, why do we need to create an efi event? To isolate the disk code from the other init code? (If so, for the same reason, we should re-write efi_init_obj_list() with events for other efi resources as well.) > > > > 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 :). My efi_disk_update() (and efi_disk_register()) is the only function visible outside the disk code, isn't it? Using some kind of events here is smart, but looks to me a bit overdoing because we anyhow have to go through all the UCLASS_BLK devices to mark whether they are still valid or not :) -Takahiro Akashi > Alex > > > > > -Takahiro Akashi > > > > > >> > >> Alex > _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
