Re: [PATCH 1/2] mmc: mmci: enable MMC_CAP_NEED_RSP_BUSY
From: Yann GAUTIER
Date: Mon Feb 08 2021 - 07:31:36 EST
On 2/5/21 1:19 PM, Yann GAUTIER wrote:
On 2/5/21 10:53 AM, Ulf Hansson wrote:
- trimmed cc-list
On Thu, 4 Feb 2021 at 13:08, <yann.gautier@xxxxxxxxxxx> wrote:
From: Yann Gautier <yann.gautier@xxxxxxxxxxx>
To properly manage commands awaiting R1B responses, the capability
MMC_CAP_NEED_RSP_BUSY is enabled in mmci driver, for variants that
manage busy detection.
This R1B management needs both the flags MMC_CAP_NEED_RSP_BUSY and
MMC_CAP_WAIT_WHILE_BUSY to be enabled together.
Would it be possible for you to share a little bit more about the
problem? Like under what circumstances does things screw up?
Is the issue only occurring when the cmd->busy_timeout becomes larger
than host->max_busy_timeout. Or even in other cases?
Signed-off-by: Yann Gautier <yann.gautier@xxxxxxxxxxx>
---
drivers/mmc/host/mmci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 1bc674577ff9..bf6971fdd1a6 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -2148,7 +2148,7 @@ static int mmci_probe(struct amba_device *dev,
if (variant->busy_dpsm_flag)
mmci_write_datactrlreg(host,
host->variant->busy_dpsm_flag);
- mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
+ mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY |
MMC_CAP_NEED_RSP_BUSY;
This isn't correct as the ux500 (and likely also other legacy
variants) don't need this. I have tried it in the past and it works
fine for ux500 without MMC_CAP_NEED_RSP_BUSY.
The difference is rather that the busy detection for stm32 variants
needs a corresponding HW busy timeout to be set (its
variant->busy_timeout flag is set). Perhaps we can use that
information instead?
Note that, MMC_CAP_NEED_RSP_BUSY, means that cmd->busy_timeout will
not be set by the core for erase commands, CMD5 and CMD6.
By looking at the code in mmci_start_command(), it looks like we will
default to a timeout of 10s, when cmd->busy_timeout isn't set. At
least for some erase requests, that won't be sufficient. Would it be
possible to disable the HW busy timeout in some way - and maybe use a
software timeout instead? Maybe I already asked Ludovic about this?
:-)
BTW, did you check that the MMCIDATATIMER does get the correct value
set for the timer in mmci_start_command() and if
host->max_busy_timeout gets correctly set in
mmci_set_max_busy_timeout()?
[...]
Kind regards
Uffe
Hi Ulf,
Thanks for the hints.
I'll check all of that and get back with updated patches.
As I tried to explain in the cover letter and in reply to Adrian, I saw
a freeze (BUSYD0) in test 37 during MMC_ERASE command with
SECURE_ERASE_ARG, when running this test just after test 36 (or any
other write test). But maybe, as you said that's mostly a incorrect
timeout issue.
Regards,
Yann
Hi,
I made some extra tests, and the timeout value set in MMCIDATATIMER
correspond to the one computed:
card->ext_csd.erase_group_def is set to 1 in mmc_init_card()
In mmc_mmc_erase_timeout(), we have:
erase_timeout = card->ext_csd.hc_erase_timeout; // 300ms * 0x07 (for the
eMMC card I have: THGBMDG5D1LBAIL
erase_timeout *= card->ext_csd.sec_erase_mult; // 0xDC
erase_timeout *= qty; // 32 (from = 0x1d0000, to = 0x20ffff)
This leads to a timeout of 14784000ms (~4 hours).
The max_busy_timeout is 86767ms.
After those 4 hours, I get this message:
mmc1: Card stuck being busy! __mmc_poll_for_busy
The second erase with MMC_ERASE_ARG finds an erase timeout of 67200ms,
and uses R1B command.
But as the first erase failed, the DPSMACT is still enabled, the busy
timeout doesn't seem to happen. Something may be missing in the error path.
Anyway, I'll push an update of the second patch of the series, and just
drop this first one.
Regards,
Yann