tifm_sd: handle non-power-of-2 block sizes

It is possible to handle arbitrary block sizes with tifm card reader by
conditionally switching to PIO in case such block has to be delivered. At
the beginning of each request, DMA is either disabled (non-power-of-2 block
size) or set to load time user preference.
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

drivers/mmc/host/tifm_sd.c

@@ -16,7 +16,6 @@
 #include <linux/mmc/host.h>
 #include <linux/highmem.h>
 #include <linux/scatterlist.h>
-#include <linux/log2.h>
 #include <asm/io.h>
 
 #define DRIVER_NAME "tifm_sd"
@@ -638,17 +637,15 @@ static void tifm_sd_request(struct mmc_host *mmc, struct mmc_request *mrq)
 		goto err_out;
 	}
 
-	if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
-		printk(KERN_ERR "%s: Unsupported block size (%d bytes)\n",
-			sock->dev.bus_id, mrq->data->blksz);
-		mrq->cmd->error = -EINVAL;
-		goto err_out;
-	}
-
 	host->cmd_flags = 0;
 	host->block_pos = 0;
 	host->sg_pos = 0;
 
+	if (mrq->data && !is_power_of_2(mrq->data->blksz))
+		host->no_dma = 1;
+	else
+		host->no_dma = no_dma ? 1 : 0;
+
 	if (r_data) {
 		tifm_sd_set_data_timeout(host, r_data);
 
@@ -676,7 +673,7 @@ static void tifm_sd_request(struct mmc_host *mmc, struct mmc_request *mrq)
 					    : PCI_DMA_FROMDEVICE)) {
 				printk(KERN_ERR "%s : scatterlist map failed\n",
 				       sock->dev.bus_id);
-				spin_unlock_irqrestore(&sock->lock, flags);
+				mrq->cmd->error = -ENOMEM;
 				goto err_out;
 			}
 			host->sg_len = tifm_map_sg(sock, r_data->sg,
@@ -692,7 +689,7 @@ static void tifm_sd_request(struct mmc_host *mmc, struct mmc_request *mrq)
 					      r_data->flags & MMC_DATA_WRITE
 					      ? PCI_DMA_TODEVICE
 					      : PCI_DMA_FROMDEVICE);
-				spin_unlock_irqrestore(&sock->lock, flags);
+				mrq->cmd->error = -ENOMEM;
 				goto err_out;
 			}
 
@@ -966,7 +963,6 @@ static int tifm_sd_probe(struct tifm_dev *sock)
 		return -ENOMEM;
 
 	host = mmc_priv(mmc);
-	host->no_dma = no_dma;
 	tifm_set_drvdata(sock, mmc);
 	host->dev = sock;
 	host->timeout_jiffies = msecs_to_jiffies(1000);