[linux-yocto] [PATCH 1/3] drivers/misc: Axxia MTC Driver Memory Initialization Check

[Bruce Ashfield]

On 2016-08-22 05:52 AM, Winkler, Tomas wrote:
>>
>> Axxia MTC driver changes:
>>  - Memory initialization completion check added
>>  - ECC error status clearing added
>>
>> Signed-off-by: Sreedevi Joshi <sreedevi.joshi at intel.com>
>> ---
>>  drivers/misc/lsi-mtc.c | 18 ++++++++++++++++++
>>  1 file changed, 18 insertions(+)
>>
>> diff --git a/drivers/misc/lsi-mtc.c b/drivers/misc/lsi-mtc.c index
>> 55c3403..f4fbe6f 100644
>> --- a/drivers/misc/lsi-mtc.c
>> +++ b/drivers/misc/lsi-mtc.c
>> @@ -31,6 +31,7 @@
>>  #include <linux/string.h>
>>  #include "linux/lsi_mtc_ioctl.h"
>>
>> +#define MTC_POLL_TIMEOUT (msecs_to_jiffies(1000))
>>
>>  /*
>>     device tree node:
>> @@ -4114,6 +4115,8 @@ static long _mtc_config(struct mtc_device *dev,
>> struct lsi_mtc_cfg_t *pMTCCfg)
>>  	struct ncp_axis_mtc_MTC_CONFIG0_REG_ADDR_r_t cfg0 = { 0 };
>>  	struct ncp_axis_mtc_MTC_CONFIG1_REG_ADDR_r_t cfg1 = { 0 };
>>  	struct ncp_axis_mtc_MTC_EXECUTE1_REG_ADDR_r_t exec1 = { 0 };
>> +	u32	init_reg = { 0 };
>> +	unsigned long tmo = 0;
>>
>>  	if ((!pMTCCfg) || (!dev))
>>  		return -EINVAL;
>> @@ -4129,6 +4132,21 @@ static long _mtc_config(struct mtc_device *dev,
>> struct lsi_mtc_cfg_t *pMTCCfg)
>>  	exec1.sw_reset = 1;
>>  	dev->regs->execute = *((u32 *) &exec1);
>>  	dev->regs->mem_init = 0x202;
>> +	/* wait for the init to complete */
>> +	tmo = jiffies + MTC_POLL_TIMEOUT;
>> +	do {
>> +		init_reg = *(&(dev->regs->mem_init));
> I'm not familiar with this code but I don't think this is the way to read a register , why not using readl(), you are at least missing memory barrier here.
>> +		if ((init_reg & 0x101) == 0x101)
>> +			break;
>> +	} while (time_before(jiffies, tmo));
> This is busy loop, how fast is that going to settle ?

I case it isn't clear, I'm waiting to hear answers to the questions
before I queue and merge this series.

cheers,

Bruce

>> +
>> +	if ((init_reg & 0x101) != 0x101) {
>> +		pr_debug("warning: mem_init failed value=0x%x
>> (expected:0x101)\n",
>> +			       init_reg);
>> +	}
>> +
>> +	/* clear ECC interrupt status */
>> +	dev->regs->ecc_int_status = 0xF;
>>
>>  	/* 3. config MTC */
>>  	cfg0 =
>> --
>> 2.7.4
>>
>> --
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