[PATCH] mmc: sdhci: fix wakeup configuration

From: Ludovic Desroches
Date: Mon Apr 25 2016 - 09:14:59 EST


Activating wakeup event is not enough to get a wakeup signal. The
corresponding events have to be enabled in the Interrupt Status Enable
Register too.

Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
---
Hi,

I just updated sdhci_enable_irq_wakeups() not sdhci_disable_irq_wakeups()
because I don't think it is necessary to configure SDHCI_INT_ENABLE at this
step, it will be done with sdhci_init() or sdhci_enable_card_detection().

While I was writing this patch, several questions came to my mind:
- Is the naming correct? wakeup signal is not an irq. 'enable_irq_wakeups' can
be a bit confusing.
- If we want to wakeup from irq, we may have to set SDHCI_INT_ENABLE and
SDHCI_SIGNAL_ENABLE and not rely on a previous configuration, isn't it?

Regards

Ludovic

drivers/mmc/host/sdhci.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index b284924..6fc69ed 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2638,18 +2638,28 @@ static irqreturn_t sdhci_thread_irq(int irq, void *dev_id)
\*****************************************************************************/

#ifdef CONFIG_PM
+/*
+ * To enable wakeup events, the corresponding events have to be enabled in
+ * the Interrupt Status Enable register too. See 'Table 1-6: Wakeup Signal
+ * Table' in the SD Host Controller Standard Specification.
+ */
void sdhci_enable_irq_wakeups(struct sdhci_host *host)
{
- u8 val;
- u8 mask = SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE
- | SDHCI_WAKE_ON_INT;
+ u8 wakeup_val;
+ u8 wakeup_mask = SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE |
+ SDHCI_WAKE_ON_INT;
+ u32 irq_val = SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE |
+ SDHCI_INT_CARD_INT;

- val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL);
- val |= mask ;
+ wakeup_val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL);
+ wakeup_val |= wakeup_mask;
/* Avoid fake wake up */
- if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)
- val &= ~(SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE);
- sdhci_writeb(host, val, SDHCI_WAKE_UP_CONTROL);
+ if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) {
+ wakeup_val &= ~(SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE);
+ irq_val &= ~(SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE);
+ }
+ sdhci_writeb(host, wakeup_val, SDHCI_WAKE_UP_CONTROL);
+ sdhci_writel(host, irq_val, SDHCI_INT_ENABLE);
}
EXPORT_SYMBOL_GPL(sdhci_enable_irq_wakeups);

--
2.5.0