From: rabin@rab.in (Rabin Vincent)
To: linux-arm-kernel@lists.infradead.org
Subject: mmci: U300 "sync with blockend" broken for multi-block?
Date: Sat, 1 Jan 2011 16:35:14 +0530 [thread overview]
Message-ID: <AANLkTimYb6TxLj4SamxRwUgykf9JyW5y9gbejOUXqZ7K@mail.gmail.com> (raw)
In MMCI, there is some code to sync between the MCI_DATABLOCKEND and the
MCI_DATAEND for U300 variants, which ensures that the transfer
terminates only when both MCI_DATABLOCKEND and MCI_DATAEND occurs:
* In the U300, the IRQs can arrive out-of-order,
* e.g. MCI_DATABLOCKEND sometimes arrives after MCI_DATAEND,
* so for this case we use the flags "blockend" and
* "dataend" to make sure both IRQs have arrived before
* concluding the transaction.
It seems to me that this code won't work correctly for multi-block
transfers, because there MCI_DATABLOCKEND will hit for the earlier
blocks and the blockend flag will be set, and if on the last block the
MCI_DATABLOCKEND hits after the MCI_DATAEND, this synching code won't do
what it's trying to do and will instead just terminate the transfer
after MCI_DATAEND.
next reply other threads:[~2011-01-01 11:05 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-01 11:05 Rabin Vincent [this message]
2011-01-01 12:10 ` mmci: U300 "sync with blockend" broken for multi-block? Russell King - ARM Linux
2011-01-05 16:15 ` Linus Walleij
2011-01-05 16:43 ` Russell King - ARM Linux
2011-01-14 20:13 ` Linus Walleij
2011-01-14 22:44 ` Russell King - ARM Linux
2011-01-16 21:11 ` Linus Walleij
2011-01-16 21:16 ` Linus Walleij
2011-01-16 22:09 ` Linus Walleij
2011-01-05 16:02 ` Linus Walleij
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