Commit e809517f authored by Pierre Ossman's avatar Pierre Ossman
Browse files

sdhci: let the controller wait for busy state to end

The sdhci controllers can interrupt us when the busy state from the
card has ended, saving CPU cycles and power.
Signed-off-by: default avatarPierre Ossman <>
parent 3fa8749e
......@@ -1266,9 +1266,31 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask)
host->cmd->error = -EILSEQ;
if (host->cmd->error)
if (host->cmd->error) {
else if (intmask & SDHCI_INT_RESPONSE)
* The host can send and interrupt when the busy state has
* ended, allowing us to wait without wasting CPU cycles.
* Unfortunately this is overloaded on the "data complete"
* interrupt, so we need to take some care when handling
* it.
* Note: The 1.0 specification is a bit ambiguous about this
* feature so there might be some problems with older
* controllers.
if (host->cmd->flags & MMC_RSP_BUSY) {
if (host->cmd->data)
DBG("Cannot wait for busy signal when also "
"doing a data transfer");
if (intmask & SDHCI_INT_RESPONSE)
......@@ -1278,11 +1300,16 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
if (!host->data) {
* A data end interrupt is sent together with the response
* for the stop command.
* The "data complete" interrupt is also used to
* indicate that a busy state has ended. See comment
* above in sdhci_cmd_irq().
if (intmask & SDHCI_INT_DATA_END)
if (host->cmd && (host->cmd->flags & MMC_RSP_BUSY)) {
if (intmask & SDHCI_INT_DATA_END) {
printk(KERN_ERR "%s: Got data interrupt 0x%08x even "
"though no data operation was in progress.\n",
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