Re: [PATCH] qcom: llcc/edac: Correct interrupt enable register configuration

[Komal Bajaj <quic_kbajaj@quicinc.com>]

On 11/20/2024 5:29 PM, Dmitry Baryshkov wrote:
> On Tue, Nov 19, 2024 at 12:16:08PM +0530, Komal Bajaj wrote:
>> The previous implementation incorrectly configured the cmn_interrupt_2_enable
>> register for interrupt handling. Using cmn_interrupt_2_enable to configure Tag,
>> Data RAM ECC interrupts would lead to issues like double handling of the
>> interrupts (EL1 and EL3) as cmn_interrupt_2_enable is meant to be configured
>> for interrupts which needs to be handled by EL3.
> This reads as if it was possible to write EL3-related register from EL1.
> Is it true?


Both EL1 and EL3 can access the LLCC "cmn_interrupt_2_enable" register, 
but configuring the register from both
EL1 & EL3 shouldn't be done as the register is meant to be configured 
from EL3. There was a bug in HPG which was
fixed recently on not to configure the register from EL1.

Thanks
Komal


>> EL1 LLCC EDAC driver needs to use cmn_interrupt_0_enable register to
>> configure Tag, Data RAM ECC interrupts instead of cmn_interrupt_2_enable.
>>
>> Fixes: 27450653f1db ("drivers: edac: Add EDAC driver support for QCOM SoCs")
>> Signed-off-by: Komal Bajaj <quic_kbajaj@quicinc.com>
>> ---
>>   drivers/edac/qcom_edac.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/edac/qcom_edac.c b/drivers/edac/qcom_edac.c
>> index a9a8ba067007..0fd7a777fe7d 100644
>> --- a/drivers/edac/qcom_edac.c
>> +++ b/drivers/edac/qcom_edac.c
>> @@ -95,7 +95,7 @@ static int qcom_llcc_core_setup(struct llcc_drv_data *drv, struct regmap *llcc_b
>>   	 * Configure interrupt enable registers such that Tag, Data RAM related
>>   	 * interrupts are propagated to interrupt controller for servicing
>>   	 */
>> -	ret = regmap_update_bits(llcc_bcast_regmap, drv->edac_reg_offset->cmn_interrupt_2_enable,
>> +	ret = regmap_update_bits(llcc_bcast_regmap, drv->edac_reg_offset->cmn_interrupt_0_enable,
>>   				 TRP0_INTERRUPT_ENABLE,
>>   				 TRP0_INTERRUPT_ENABLE);
>>   	if (ret)
>> @@ -113,7 +113,7 @@ static int qcom_llcc_core_setup(struct llcc_drv_data *drv, struct regmap *llcc_b
>>   	if (ret)
>>   		return ret;
>>
>> -	ret = regmap_update_bits(llcc_bcast_regmap, drv->edac_reg_offset->cmn_interrupt_2_enable,
>> +	ret = regmap_update_bits(llcc_bcast_regmap, drv->edac_reg_offset->cmn_interrupt_0_enable,
>>   				 DRP0_INTERRUPT_ENABLE,
>>   				 DRP0_INTERRUPT_ENABLE);
>>   	if (ret)
>> --
>> 2.46.0
>>