Re: [PATCH 01/28] OMAP3: PM: GPMC context save/restore

Kevin Hilman
2009-10-05T17:30:39Z

Nishanth Menon <menon.nishanth@gmail.com> writes:

[...]

>> +void omap3_gpmc_save_context()
>> +{
>> + int i;
>> + gpmc_context.sysconfig = gpmc_read_reg(GPMC_SYSCONFIG);
>> + gpmc_context.irqenable = gpmc_read_reg(GPMC_IRQENABLE);
>> + gpmc_context.timeout_ctrl = gpmc_read_reg(GPMC_TIMEOUT_CONTROL);
>> + gpmc_context.config = gpmc_read_reg(GPMC_CONFIG);
>> + gpmc_context.prefetch_config1 = gpmc_read_reg(GPMC_PREFETCH_CONFIG1);
>> + gpmc_context.prefetch_config2 = gpmc_read_reg(GPMC_PREFETCH_CONFIG2);
>> + gpmc_context.prefetch_control = gpmc_read_reg(GPMC_PREFETCH_CONTROL);
>> + for (i = 0; i < GPMC_CS_NUM; i++) {
>> + gpmc_context.cs_context[i].is_valid =
>> + (gpmc_cs_read_reg(i, GPMC_CS_CONFIG7))
>> + & GPMC_CONFIG7_CSVALID;
>> + if (gpmc_context.cs_context[i].is_valid) {
>> + gpmc_context.cs_context[i].config1 =
>> + gpmc_cs_read_reg(i, GPMC_CS_CONFIG1);
>> + gpmc_context.cs_context[i].config2 =
>> + gpmc_cs_read_reg(i, GPMC_CS_CONFIG2);
>> + gpmc_context.cs_context[i].config3 =
>> + gpmc_cs_read_reg(i, GPMC_CS_CONFIG3);
>> + gpmc_context.cs_context[i].config4 =
>> + gpmc_cs_read_reg(i, GPMC_CS_CONFIG4);
>> + gpmc_context.cs_context[i].config5 =
>> + gpmc_cs_read_reg(i, GPMC_CS_CONFIG5);
>> + gpmc_context.cs_context[i].config6 =
>> + gpmc_cs_read_reg(i, GPMC_CS_CONFIG6);
>> + gpmc_context.cs_context[i].config7 =
>> + gpmc_cs_read_reg(i, GPMC_CS_CONFIG7);
>> + }
>>
> here is a theoretical bug:
> 1: GPMC, 1, 2, 3 4 5 configured 6 7 not configured.
> 2. Save and restore 1: save and restore variables which are static will
> contain 1-5 and not 6&7
> 3. next I disable 2,3
> 3. save will save 1,4,5 BUT my variable will contain 1,2,3,4,5 ->
> restore will rename 2,3 (which I did not intend)..

Not sure I follow the problem here. What do you mean by "rename".
The saved context will have values for 2 and 3, but the is_valid
flag will not be set, so they shouldn't be used.

Rajendra was the original author of these, so maybe I'm not fully
understanding here, but disabling a GPMC looks to me like it
will disable both the save and restore.

Kevin