On 2016-11-22 8:12 PM, Jisheng Zhang wrote:
On Tue, 22 Nov 2016 19:48:56 -0800 Jeremy McNicoll wrote:
On 2016-11-22 7:36 PM, Jisheng Zhang wrote:
On Tue, 22 Nov 2016 17:09:48 -0800
Jeremy McNicoll <jeremymc@xxxxxxxxxx> wrote:
On msm8992 it has been observed that IRQs were not getting
ACK'd correctly when clocked at speeds greater than 400KHz.
Signed-off-by: Jeremy McNicoll <jeremymc@xxxxxxxxxx>
---
drivers/mmc/host/sdhci-msm.c | 7 +++++++
drivers/mmc/host/sdhci.c | 12 ++++++++++--
drivers/mmc/host/sdhci.h | 2 ++
3 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 1fcda96..459003c 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -1303,6 +1303,13 @@ static int sdhci_msm_probe(struct platform_device *pdev)
CORE_VENDOR_SPEC_CAPABILITIES0);
}
+ /* Enable delayed IRQ handling workaround on 8992 */
+ if (core_major == 1 && core_minor == 0x3e) {
+ /* Add 40us delay in interrupt handler when operating
+ * at initialization frequency of 400KHz. */
+ host->quirks2 |= SDHCI_QUIRK2_SLOW_INT_CLR;
+ }
+
/* Setup IRQ for handling power/voltage tasks with PMIC */
msm_host->pwr_irq = platform_get_irq_byname(pdev, "pwr_irq");
if (msm_host->pwr_irq < 0) {
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 5911f98..c1aae22 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2703,11 +2703,19 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
result = IRQ_WAKE_THREAD;
}
- if (intmask & SDHCI_INT_CMD_MASK)
+ if (intmask & SDHCI_INT_CMD_MASK) {
+ if ((host->quirks2 & SDHCI_QUIRK2_SLOW_INT_CLR) && (host->clock <= 400000)) {
+ udelay(40);
+ }
sdhci_cmd_irq(host, intmask & SDHCI_INT_CMD_MASK);
+ }
- if (intmask & SDHCI_INT_DATA_MASK)
+ if (intmask & SDHCI_INT_DATA_MASK) {
+ if ((host->quirks2 & SDHCI_QUIRK2_SLOW_INT_CLR) && (host->clock <= 400000)) {
+ udelay(40);
+ }
sdhci_data_irq(host, intmask & SDHCI_INT_DATA_MASK);
+ }
if (intmask & SDHCI_INT_BUS_POWER)
pr_err("%s: Card is consuming too much power!\n",
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index c055e24..5f8301e 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -24,6 +24,8 @@
* Controller registers
*/
+#define SDHCI_QUIRK2_SLOW_INT_CLR (1<<5)
IIRC, new quirk isn't allowed now.
Why not?
IIRC, mmc subsystem will behave as a lib in the long run, so the community
and developers call for no new quirk. For your case, we may need to handle
the udelay in sdhci-msm.c, export sdhci_irq as a helper function?
Thanks for the details and suggestions. I am going to wait until the US
Thanksgiving (and cyber Monday) is over before I do any more.
-jeremy
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