mmc: moxart: Add MOXA ART SD/MMC driver

Hello Jonas Jensen,

The patch 1b66e94e6b99: "mmc: moxart: Add MOXA ART SD/MMC driver" from Apr 9, 2014, leads to the following static checker warning:

drivers/mmc/host/moxart-mmc.c:691 moxart_remove()
warn: variable dereferenced before check 'mmc' (see line 687)

drivers/mmc/host/moxart-mmc.c
684 static int moxart_remove(struct platform_device *pdev) 685 {
686 struct mmc_host *mmc = dev_get_drvdata(&pdev->dev);

   687          struct moxart_host *host = mmc_priv(mmc);
                                           ^^^^^^^^^^^^^

Dereference.

688
689 dev_set_drvdata(&pdev->dev, NULL);
690

   691          if (mmc) {
                    ^^^

Check.

692 if (!IS_ERR(host->dma_chan_tx))

regards,
dan carpenter

Right, the check should just be removed, because the moxart_remove function will not be called unless moxart_probe() has successfully set the drvdata.

On a related note, I also found two bugs using automated build testing:

a) The driver should use dma_request_slave_channel_reason() instead of of_dma_request_slave_channel() so it can be compiled when CONFIG_OF is disabled.

b) moxart_remove() contains an extraneous kfree(host), where host is a variable that has already been freed at that point.

Arnd

Thanks, I'll post a patch with fixes for this and bugs spotted by Arnd.

Regards,
Jonas