[bug report] mmc: dw_mmc: Remove struct dw_mci_slot

[Dan Carpenter <dan.carpenter@linaro.org>]

Hello Shawn Lin,

Commit 926311cf3361 ("mmc: dw_mmc: Remove struct dw_mci_slot") from
Dec 16, 2025 (linux-next), leads to the following Smatch static
checker warning:

	drivers/mmc/host/dw_mmc.c:3467 dw_mci_remove()
	error: we previously assumed 'host' could be null (see line 3464)

drivers/mmc/host/dw_mmc.c
    3457         return ret;
    3458 }
    3459 EXPORT_SYMBOL(dw_mci_probe);
    3460 
    3461 void dw_mci_remove(struct dw_mci *host)
    3462 {
    3463         dev_dbg(host->dev, "remove host\n");
                         ^^^^^^^^^
Host is dereferenced

    3464         if (host)

Then checked for NULL.

    3465                 dw_mci_cleanup_host(host);

The dw_mci_cleanup_host() function gives up our claim to host which
allows it to be re-used.

    3466 
--> 3467         mci_writel(host, RINTSTS, 0xFFFFFFFF);

So it's surprising to me that we keep on using it throughout the
rest of the function.

    3468         mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */
    3469 
    3470         /* disable clock to CIU */
    3471         mci_writel(host, CLKENA, 0);
    3472         mci_writel(host, CLKSRC, 0);
    3473 
    3474         if (host->use_dma && host->dma_ops->exit)
    3475                 host->dma_ops->exit(host);
    3476 
    3477         reset_control_assert(host->pdata->rstc);
    3478 
    3479         clk_disable_unprepare(host->ciu_clk);
    3480         clk_disable_unprepare(host->biu_clk);
    3481 }

regards,
dan carpenter