On 1 September 2011 21:19, S, Venkatraman <svenkatr@xxxxxx> wrote:
> On Mon, Aug 29, 2011 at 3:38 AM, Per Forlin <per.forlin@xxxxxxxxxx> wrote:
>> Reported by Russell King:
>> ------------
>> mmcblk0: error -84 transferring data, sector 149201, nr 64,
>> cmd response 0x900, card status 0xb00
>> mmcblk0: retrying using single block read
>>
>> WARNING: at /home/rmk/git/linux-2.6-rmk/lib/dma-debug.c:811 check_unmap
>> omap_hsmmc omap_hsmmc.0: DMA-API: device driver tries to free DMA memory
>> it has not allocated [device address=0x0000000080933000] [size=20480 bytes]
>> -------------
>>
>> In case of an error dma_unmap() is issued in omap_hsmmc_dma_cleanup()
>> and then again in omap_hsmmc_post_req(). Resolve this by clearing the
>> host_cookie to indicate there is no DMA mapped memory to unmap.
>>
>> Signed-off-by: Per Forlin <per.forlin@xxxxxxxxxx>
>> ---
>> Bug fix on 3.1-rc3
>>
>> drivers/mmc/host/omap_hsmmc.c | 7 +++++--
>> 1 files changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
>> index 21e4a79..31d9817 100644
>> --- a/drivers/mmc/host/omap_hsmmc.c
>> +++ b/drivers/mmc/host/omap_hsmmc.c
>> @@ -1011,6 +1011,7 @@ static void omap_hsmmc_dma_cleanup(struct omap_hsmmc_host *host, int errno)
>> host->data->sg_len,
>> omap_hsmmc_get_dma_dir(host, host->data));
>> omap_free_dma(dma_ch);
>> + host->data->host_cookie = 0;
>> }
>> host->data = NULL;
>> }
>> @@ -1576,8 +1577,10 @@ static void omap_hsmmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
>> struct mmc_data *data = mrq->data;
>>
>> if (host->use_dma) {
>> - dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
>> - omap_hsmmc_get_dma_dir(host, data));
>> + if (data->host_cookie)
>> + dma_unmap_sg(mmc_dev(host->mmc), data->sg,
>> + data->sg_len,
>> + omap_hsmmc_get_dma_dir(host, data));
>> data->host_cookie = 0;
>> }
>> }
>> --
>> 1.7.4.1
>>
>>
>
> I just posted a patch [1] which just consolidates all unmapping to
> just post_req.
> This would obviously prevent double unmapping, and keeps all the related
> dma operations at a single place. Let me know if that works better.
>
I'm in favour of such patch. My patch only tries to do the minimal bug fix.
I have been out of office the last 10 days or so. I'll look at your
patch later today.
Thanks,
Per
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