Hi, Ulf.
On 08/17/2015 07:16 PM, Ulf Hansson wrote:
> On 3 August 2015 at 17:04, Heiko Stübner <heiko@xxxxxxxxx> wrote:
>> The dw_mci_init_dma() may decide to not use dma, but pio instead, caused
>> by things like wrong dma settings in the system.
>>
>> Till now the code dw_mci_init_slot() always assumed that dma is available
>> when CONFIG_MMC_DW_IDMAC was defined, ignoring the host->use_dma var
>> set during dma init.
>>
>> So when now the dma init failed for whatever reason, the transfer sizes
>> would still be set for dma transfers, especially including the maximum
>> block-count calculated from host->ring_size and resulting in a
>>
>> [ 4.991109] ------------[ cut here ]------------
>> [ 4.991111] kernel BUG at drivers/mmc/core/core.c:256!
>> [ 4.991113] Internal error: Oops - BUG: 0 [#1] SMP ARM
>>
>> because host->ring_size is 0 in this case and the slot init code uses
>> the wrong code to calculate the values.
>>
>> Fix this by selecting the correct calculations using the host->use_dma
>> variable instead of the CONFIG_MMC_DW_IDMAC config option.
>>
>> Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx>
>> ---
>> drivers/mmc/host/dw_mmc.c | 27 ++++++++++++++-------------
>> 1 file changed, 14 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 40e9d8e..9ec3521 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -2391,19 +2391,20 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
>> mmc->max_seg_size = host->pdata->blk_settings->max_seg_size;
>> } else {
>> /* Useful defaults if platform data is unset. */
>> -#ifdef CONFIG_MMC_DW_IDMAC
>> - mmc->max_segs = host->ring_size;
>> - mmc->max_blk_size = 65536;
>> - mmc->max_seg_size = 0x1000;
>> - mmc->max_req_size = mmc->max_seg_size * host->ring_size;
>> - mmc->max_blk_count = mmc->max_req_size / 512;
>> -#else
>> - mmc->max_segs = 64;
>> - mmc->max_blk_size = 65536; /* BLKSIZ is 16 bits */
>> - mmc->max_blk_count = 512;
>> - mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
>> - mmc->max_seg_size = mmc->max_req_size;
>> -#endif /* CONFIG_MMC_DW_IDMAC */
>> + if (host->use_dma) {
>> + mmc->max_segs = host->ring_size;
>
> I expect this may cause a compiler error since host->ring_size is only
> available in the struct dw_mci *host when CONFIG_MMC_DW_IDMAC is set.
>
> I have already pulled in this patch from Jaehoon's pull request.
> Perhaps I should only amend the patch and change the host->ring_size
> to be always available no matter if CONFIG_MMC_DW_IDMAC is set or not?
Sorry for this. if you can, i think good that CONFIG_MMC_DW_IDMAC is removed at struct dw_mci.
Could you amend it?
If you want to get patch, i will send patch at now.
Best Regards,
Jaehoon Chung
>
>> + mmc->max_blk_size = 65536;
>> + mmc->max_seg_size = 0x1000;
>> + mmc->max_req_size = mmc->max_seg_size * host->ring_size;
>> + mmc->max_blk_count = mmc->max_req_size / 512;
>> + } else {
>> + mmc->max_segs = 64;
>> + mmc->max_blk_size = 65536; /* BLKSIZ is 16 bits */
>> + mmc->max_blk_count = 512;
>> + mmc->max_req_size = mmc->max_blk_size *
>> + mmc->max_blk_count;
>> + mmc->max_seg_size = mmc->max_req_size;
>> + }
>> }
>>
>> if (dw_mci_get_cd(mmc))
>> --
>> 2.1.4
>>
>>
>
> Kind regards
> Uffe
>
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