Hi Kishon,
On 20/11/18 10:23 AM, Kishon Vijay Abraham I wrote:
> 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).
>
host->ier is modified everywhere during an mmc request. I would not
expect it to hold its value after so many tuning commands. I can add a
bool to check of DCRC was enabled before and only then re-enable it.
Thanks,
Faiz
