Re: [PATCH V2 12/15] coresight: tmc: keep track of memory width

From: Mathieu Poirier
Date: Fri Apr 15 2016 - 12:11:04 EST


On 14 April 2016 at 05:19, Suzuki K Poulose <Suzuki.Poulose@xxxxxxx> wrote:
> On 12/04/16 18:54, Mathieu Poirier wrote:
>>
>> Accessing the HW configuration register each time the memory
>> width is needed simply doesn't make sense. It is much more
>> efficient to read the value once and keep a reference for
>> later use.
>>
>> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>> ---
>> drivers/hwtracing/coresight/coresight-tmc-etf.c | 8 +++-----
>> drivers/hwtracing/coresight/coresight-tmc.c | 1 +
>> drivers/hwtracing/coresight/coresight-tmc.h | 2 ++
>> 3 files changed, 6 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c
>> b/drivers/hwtracing/coresight/coresight-tmc-etf.c
>> index 50d32e8ef4ea..a440784e3b27 100644
>> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
>> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
>> @@ -41,18 +41,16 @@ void tmc_etb_enable_hw(struct tmc_drvdata *drvdata)
>>
>> static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata)
>> {
>> - enum tmc_mem_intf_width memwidth;
>> u8 memwords;
>> char *bufp;
>> u32 read_data;
>> int i;
>>
>> - memwidth = BMVAL(readl_relaxed(drvdata->base + CORESIGHT_DEVID),
>> 8, 10);
>> - if (memwidth == TMC_MEM_INTF_WIDTH_32BITS)
>> + if (drvdata->memwidth == TMC_MEM_INTF_WIDTH_32BITS)
>> memwords = 1;
>> - else if (memwidth == TMC_MEM_INTF_WIDTH_64BITS)
>> + else if (drvdata->memwidth == TMC_MEM_INTF_WIDTH_64BITS)
>> memwords = 2;
>> - else if (memwidth == TMC_MEM_INTF_WIDTH_128BITS)
>> + else if (drvdata->memwidth == TMC_MEM_INTF_WIDTH_128BITS)
>> memwords = 4;
>
>
>
>> struct tmc_drvdata {
>> @@ -118,6 +119,7 @@ struct tmc_drvdata {
>> u32 size;
>> local_t mode;
>> enum tmc_config_type config_type;
>> + enum tmc_mem_intf_width memwidth;
>
>
> Could we not store the converted memwords here, instead of the enum value
> here
> and convert it every time we access it ?

Sure, I can fix that.

Thanks for the review,
Mathieu

>
> Cheers
> Suzuki