On 1/10/19 10:22 AM, Alexander Graf wrote: > > >> Am 10.01.2019 um 10:16 schrieb AKASHI Takahiro <takahiro.aka...@linaro.org>: >> >>> 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.
Why shouldn't we partially initialize the EFI environment when the first block device is created? I think only the memory part of EFI is needed at this stage. >> >> This event will be expected to be 'signal'ed at every creation/deletion >> of UCLASS_BLK device. Right? > > Correct. Events are not the EFI way of handling drivers. Drivers are connected by calling ConnectController. Please, add two new functions in lib/efi_loader/efi_disk.c * one called after a new block device is created * another called before a device is destroyed both passing as argument (struct udevice *dev) and the caller being in drivers/block/blk-uclass.c A separate patch has to add a struct udevice *dev field to struct efi_obj and let efi_block_driver use it to decide if a new device shall be created when binding. In efi_block_driver.c we have to implement the unbind function. In a later patch series we will use said functions to create or destroy a handle with the EFI_BLOCK_IO_PROTOCOL and wire up ConnectController and DisconnectController. Best regards Heinrich > >> >>> 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(). > > We already walk through the event list on any u-boot/efi world switch. > >> >>> 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. > > Right, and that signal_event() will happen the next time we go back into efi > land. By that time, the dm blk struct will be complete. > >> >> If so, why do we need to create an efi event? To isolate the disk code >> from the other init code? > > I don't think we should call init code during runtime, yes. These are 2 paths. > >> >> (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 :) > > What do you mean? > > Alex > > > _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
