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sdhci: Add quirk for controllers that need small delays for PIO

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Small udelay is needed to make eSDHC work in PIO mode. Without
the delay reading causes endless interrupt storm, and writing
corrupts data. The first guess would be that we must wait for
some bit in some register, but I didn't find any reliable bits
that change before and after the delay.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This commit is contained in:
Anton Vorontsov
2009-03-17 00:14:00 +03:00
committed by Pierre Ossman
parent 8114634ccb
commit 3e3bf20756
2 changed files with 5 additions and 0 deletions
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3
drivers/mmc/host/sdhci.c
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@@ -336,6 +336,9 @@ static void sdhci_transfer_pio(struct sdhci_host *host)
mask = ~0;
while (sdhci_readl(host, SDHCI_PRESENT_STATE) & mask) {
if (host->quirks & SDHCI_QUIRK_PIO_NEEDS_DELAY)
udelay(100);
if (host->data->flags & MMC_DATA_READ)
sdhci_read_block_pio(host);
else