Re: mmc: rtsx: add support for pre_req and post_req

[micky <micky_ching@realsil.com.cn>]

Hi Dan,

I'm wondering how to get this warning info, so I can check before 
sending patch.
Can you give me some idea?

Best Regards.
micky.


On 02/25/2014 06:03 AM, Dan Carpenter wrote:
> Hello Micky Ching,
>
> This is a semi-automatic email about new static checker warnings.
>
> The patch c42deffd5b53: "mmc: rtsx: add support for pre_req and
> post_req" from Feb 17, 2014, leads to the following Smatch complaint:
>
> drivers/mmc/host/rtsx_pci_sdmmc.c:194 sd_finish_request()
> 	 error: we previously assumed 'mrq' could be null (see line 158)
> drivers/mmc/host/rtsx_pci_sdmmc.c
>     157		mrq = host->mrq;
>     158		if (!mrq) {
>                      ^^^^
> Patch introduces check.
>
>     159			dev_err(sdmmc_dev(host), "error: no request need finish\n");
>     160			goto out;
>     161		}
>     162	
>     163		cmd = mrq->cmd;
>     164		data = mrq->data;
>     165	
>     166		any_error = (mrq->sbc && mrq->sbc->error) ||
>     167			(mrq->stop && mrq->stop->error) ||
>     168			(cmd && cmd->error) || (data && data->error);
>     169	
>     170		if (any_error) {
>     171			rtsx_pci_stop_cmd(pcr);
>     172			sd_clear_error(host);
>     173		}
>     174	
>     175		if (data) {
>     176			if (any_error)
>     177				data->bytes_xfered = 0;
>     178			else
>     179				data->bytes_xfered = data->blocks * data->blksz;
>     180	
>     181			if (!data->host_cookie)
>     182				rtsx_pci_dma_unmap_sg(pcr, data->sg, data->sg_len,
>     183						data->flags & MMC_DATA_READ);
>     184	
>     185		}
>     186	
>     187		host->mrq = NULL;
>     188		host->cmd = NULL;
>     189		host->data = NULL;
>     190	
>     191	out:
>     192		spin_unlock_irqrestore(&host->lock, flags);
>     193		mutex_unlock(&pcr->pcr_mutex);
>     194		mmc_request_done(host->mmc, mrq);
>                                              ^^^
> Dereferenced inside function.  Patch introduces dereference.
>
>     195	}
>     196	
>
> regards,
> dan carpenter
> .
>