> 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. > > This event will be expected to be 'signal'ed at every creation/deletion > of UCLASS_BLK device. Right?
Correct. > >> 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
