A38x BootROM MMC_CMD_SEND_STATUS timeouts

[Pali Rohár]

Can anybody help with this?

On Saturday 25 March 2023 13:25:06 Pali Rohár wrote:
> CCing MMC maintainers (Peng Fan & Jaehoon Chung). Could you help us with
> this issue? Expected usage is following: BootROM reads and execute SPL
> from eMMC (BootROM has its own code for reading eMMC), SPL initialize
> mmc driver and after SPL finish its work it returns control back to
> BootROM and BootROM reads and execute proper U-Boot from eMMC. And issue
> is that after SPL returns control back to BootROM it looks like that
> BootROM is sending MMC_CMD_SEND_STATUS command to eMMC but it timeouts
> (timeout takes 5 minutes!) and after it correctly reads proper U-Boot
> from eMMC and continues booting proper U-Boot. I guess that there is an
> issue that SPL's mmc driver changes eMMC state into something which
> BootROM does not expect.
> 
> On Friday 24 March 2023 02:55:55 Martin Rowe wrote:
> > On Thu, 23 Mar 2023 at 19:01, Pali Rohár <pali at kernel.org> wrote:
> > > There is issue with that 5 minutes delay. But I think it should be fixed
> > > by the patch which I sent earlier, which restore partition config based
> > > on mmc->part_config in board_return_to_bootrom(). Could you test it?
> > > https://lore.kernel.org/u-boot/20230305160416.xc7wlzmkaociwcf7@pali/
> > > Now when mmc->part_config is correctly initialized it should restore
> > > configuration and BootROM does not have to get that "Timeout waiting
> > > card ready" error.
> > 
> > Still takes about 5 minutes. The output is below with MMC tracing. I
> > confirmed the value of mmc->part_config used for
> > restore_emmc_boot_part_config is the same as what is initially
> > detected early in SPL (both are 10 with mmc partconf 0 0 1 1 and
> > zeroed boot0).
> > 
> > ERROR: Invalid kwbimage v1
> > mmc_load_image_raw_sector: mmc block read error
> > spl: mmc: wrong boot mode
> > Trying to boot from BOOTROM
> > CMD_SEND:6
> >         ARG             0x03b30a00
> >         MMC_RSP_R1b         0x00000900
> > CMD_SEND:13
> >         ARG             0x00010000
> >         MMC_RSP_R1,5,6,7      0x00000900
> > CURR STATE:4
> > Returning to BootROM (return address 0xffff05c4)...
> 
> I looked at the BootROM disassembled code and error message
> "Timeout waiting card ready" is printed when following mmc command
> cmdidx=0xd, resptype=0x15, cmdarg=(something)<<0x10 timeouts.
> 
> 0xd is in U-Boot MMC_CMD_SEND_STATUS
> 
> 0x15 is in U-Boot MMC_RSP_PRESENT|MMC_RSP_136|MMC_RSP_CRC|MMC_RSP_BUSY
> which looks like U-Boot's MMC_RSP_R2 with BUSY bit set
> 
> It looks like U-Boot function mmc_send_status() where that "something"
> in cmdarg is mmc->rca.
> 
> If command does not timeout then BootROM next checks if response has
> BIT(8) set and if response mask 0x1e00 matches value 0xe00. If both are
> truth then BootROM mark call as successful.
> 
> If response ANDed with mask 0xfdf94080 is non-zero then BootROM prints
> "Status Error: " with hex response value and mark call as unsuccessful.
> 
> I'm looking at the U-Boot code and this BootROM logic looks very similar
> to U-Boot function mmc_poll_for_busy(), just without first call
> mmc_wait_dat0().
> 
> BIT(8) is MMC_STATUS_RDY_FOR_DATA
> 0x1e00 is MMC_STATUS_CURR_STATE
> 0xe00 is MMC_STATE_PRG
> 0xfdf94080 is MMC_STATUS_MASK
> 
> I'm not mmc expert, but this looks like MMC_CMD_SEND_STATUS is failing
> in BootROM after U-Boot returns control back to the BootROM.