Thread (32 messages) 32 messages, 5 authors, 2018-03-14
STALE3039d REVIEWED: 3 (3M)
Revisions (5)
  1. v1 [diff vs current]
  2. v2 current
  3. v3 [diff vs current]
  4. v4 [diff vs current]
  5. v5 [diff vs current]

[PATCH v2 05/16] mmc: sdhci-omap: Workaround for Errata i802

From: Kishon Vijay Abraham I <hidden>
Date: 2018-02-05 12:52:17
Also in: linux-devicetree, linux-mmc, linux-omap, lkml
Subsystem: multimedia card (mmc), secure digital (sd) and sdio subsystem, secure digital host controller interface (sdhci) driver, secure digital host controller interface (sdhci) ti omap driver, the rest · Maintainers: Ulf Hansson, Adrian Hunter, Vignesh Raghavendra, Linus Torvalds

Errata i802 in AM572x Sitara Processors Silicon Revision 2.0, 1.1
(SPRZ429K July 2014?Revised March 2017 [1]) mentions
DCRC error interrupts (MMCHS_STAT[21] DCRC=0x1) can occur
during the tuning procedure and it has to be disabled during the
tuning procedure Implement workaround for Errata i802 here..

[1] -> http://www.ti.com/lit/er/sprz429k/sprz429k.pdf

Signed-off-by: Kishon Vijay Abraham I <redacted>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci-omap.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)
diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
index 36e0626d3de2..e24ae903f7ba 100644
--- a/drivers/mmc/host/sdhci-omap.c
+++ b/drivers/mmc/host/sdhci-omap.c
@@ -257,6 +257,7 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	u32 start_window = 0, max_window = 0;
 	u8 cur_match, prev_match = 0;
 	u32 length = 0, max_len = 0;
+	u32 ier = host->ier;
 	u32 phase_delay = 0;
 	int ret = 0;
 	u32 reg;
@@ -277,6 +278,16 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	reg |= DLL_SWT;
 	sdhci_omap_writel(omap_host, SDHCI_OMAP_DLL, reg);
 
+	/*
+	 * OMAP5/DRA74X/DRA72x Errata i802:
+	 * DCRC error interrupts (MMCHS_STAT[21] DCRC=0x1) can occur
+	 * during the tuning procedure. So disable it during the
+	 * tuning procedure.
+	 */
+	ier &= ~SDHCI_INT_DATA_CRC;
+	sdhci_writel(host, ier, SDHCI_INT_ENABLE);
+	sdhci_writel(host, ier, SDHCI_SIGNAL_ENABLE);
+
 	while (phase_delay <= MAX_PHASE_DELAY) {
 		sdhci_omap_set_dll(omap_host, phase_delay);
 
@@ -322,6 +333,8 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
 
 ret:
 	sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
+	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
+	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
 	return ret;
 }
 
-- 
2.11.0
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help