Re: [PATCH 1/4] mmc: sdhci-omap: Fix DCRC error handling during tuning

From: Kishon Vijay Abraham I
Date: Mon Nov 19 2018 - 23:53:21 EST


Hi,

On 19/11/18 4:46 PM, Faiz Abbas wrote:
Commit 7d33c3581536 ("mmc: sdhci-omap: Workaround for Errata i802")
disabled DCRC interrupts during tuning. This write to the interrupt
enable register gets overwritten in sdhci_prepare_data() and the
interrupt is not in fact disabled. Fix this by disabling the interrupt
in the host->ier variable.

Signed-off-by: Faiz Abbas <faiz_abbas@xxxxxx>
---
drivers/mmc/host/sdhci-omap.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
index 88347ce78f23..87138067e334 100644
--- a/drivers/mmc/host/sdhci-omap.c
+++ b/drivers/mmc/host/sdhci-omap.c
@@ -290,7 +290,6 @@ 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;
@@ -317,9 +316,7 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
* 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);
+ host->ier &= ~SDHCI_INT_DATA_CRC;
while (phase_delay <= MAX_PHASE_DELAY) {
sdhci_omap_set_dll(omap_host, phase_delay);
@@ -366,6 +363,8 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
ret:
sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
+ /* Reenable forbidden interrupt */
+ host->ier |= SDHCI_INT_DATA_CRC;

It's better to have a backup of host->ier and restore the value here (in case DATA_CRC is disabled for other cases).

Thanks
Kishon