Commit 68c5ed59 authored by Ben Dooks's avatar Ben Dooks Committed by Linus Torvalds

s3cmci: DMA fixes

Fixes for the DMA transfer mode of the driver to try and improve the state
of the code:

- Ensure that dma_complete is set during the end of the command phase
  so that transfers do not stall awaiting the completion

- Update the DMA debugging to provide a bit more useful information
  such as how many DMA descriptors where not processed and print the
  DMA addresses in hexadecimal.

- Fix the DMA channel request code to actually request DMA for the
  S3CMCI block instead of whatever '0' signified.

- Add fallback to PIO if we cannot get the DMA channel, as many of the
  devices with this block only have a limited number of DMA channels.

- Only try and claim and free the DMA channel if we are trying to use it.

This improves the driver DMA code to the point where it can now identify a
card and read the partition table.  However the DMA can still stall when
trying to move data between the host and memory.
Signed-off-by: default avatarBen Dooks <ben@simtec.co.uk>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 26f14947
...@@ -183,6 +183,21 @@ static inline bool s3cmci_host_usedma(struct s3cmci_host *host) ...@@ -183,6 +183,21 @@ static inline bool s3cmci_host_usedma(struct s3cmci_host *host)
#endif #endif
} }
/**
* s3cmci_host_canpio - return true if host has pio code available
*
* Return true if the driver has been compiled with the PIO support code
* available.
*/
static inline bool s3cmci_host_canpio(void)
{
#ifdef CONFIG_MMC_S3C_PIO
return true;
#else
return false;
#endif
}
static inline u32 enable_imask(struct s3cmci_host *host, u32 imask) static inline u32 enable_imask(struct s3cmci_host *host, u32 imask)
{ {
u32 newmask; u32 newmask;
...@@ -786,6 +801,7 @@ static void s3cmci_dma_done_callback(struct s3c2410_dma_chan *dma_ch, ...@@ -786,6 +801,7 @@ static void s3cmci_dma_done_callback(struct s3c2410_dma_chan *dma_ch,
dbg(host, dbg_dma, "DMA FINISHED Size:%i DSTA:%08x DCNT:%08x\n", dbg(host, dbg_dma, "DMA FINISHED Size:%i DSTA:%08x DCNT:%08x\n",
size, mci_dsta, mci_dcnt); size, mci_dsta, mci_dcnt);
host->dma_complete = 1;
host->complete_what = COMPLETION_FINALIZE; host->complete_what = COMPLETION_FINALIZE;
out: out:
...@@ -816,7 +832,8 @@ static void finalize_request(struct s3cmci_host *host) ...@@ -816,7 +832,8 @@ static void finalize_request(struct s3cmci_host *host)
if (cmd->data && (cmd->error == 0) && if (cmd->data && (cmd->error == 0) &&
(cmd->data->error == 0)) { (cmd->data->error == 0)) {
if (s3cmci_host_usedma(host) && (!host->dma_complete)) { if (s3cmci_host_usedma(host) && (!host->dma_complete)) {
dbg(host, dbg_dma, "DMA Missing!\n"); dbg(host, dbg_dma, "DMA Missing (%d)!\n",
host->dma_complete);
return; return;
} }
} }
...@@ -1065,7 +1082,7 @@ static int s3cmci_prepare_pio(struct s3cmci_host *host, struct mmc_data *data) ...@@ -1065,7 +1082,7 @@ static int s3cmci_prepare_pio(struct s3cmci_host *host, struct mmc_data *data)
static int s3cmci_prepare_dma(struct s3cmci_host *host, struct mmc_data *data) static int s3cmci_prepare_dma(struct s3cmci_host *host, struct mmc_data *data)
{ {
int dma_len, i; int dma_len, i;
int rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0; int rw = data->flags & MMC_DATA_WRITE;
BUG_ON((data->flags & BOTH_DIR) == BOTH_DIR); BUG_ON((data->flags & BOTH_DIR) == BOTH_DIR);
...@@ -1073,7 +1090,7 @@ static int s3cmci_prepare_dma(struct s3cmci_host *host, struct mmc_data *data) ...@@ -1073,7 +1090,7 @@ static int s3cmci_prepare_dma(struct s3cmci_host *host, struct mmc_data *data)
s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH); s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH);
dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len, dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
(rw) ? DMA_TO_DEVICE : DMA_FROM_DEVICE); rw ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
if (dma_len == 0) if (dma_len == 0)
return -ENOMEM; return -ENOMEM;
...@@ -1084,11 +1101,11 @@ static int s3cmci_prepare_dma(struct s3cmci_host *host, struct mmc_data *data) ...@@ -1084,11 +1101,11 @@ static int s3cmci_prepare_dma(struct s3cmci_host *host, struct mmc_data *data)
for (i = 0; i < dma_len; i++) { for (i = 0; i < dma_len; i++) {
int res; int res;
dbg(host, dbg_dma, "enqueue %i:%u@%u\n", i, dbg(host, dbg_dma, "enqueue %i: %08x@%u\n", i,
sg_dma_address(&data->sg[i]), sg_dma_address(&data->sg[i]),
sg_dma_len(&data->sg[i])); sg_dma_len(&data->sg[i]));
res = s3c2410_dma_enqueue(host->dma, (void *) host, res = s3c2410_dma_enqueue(host->dma, host,
sg_dma_address(&data->sg[i]), sg_dma_address(&data->sg[i]),
sg_dma_len(&data->sg[i])); sg_dma_len(&data->sg[i]));
...@@ -1581,8 +1598,6 @@ static int __devinit s3cmci_probe(struct platform_device *pdev) ...@@ -1581,8 +1598,6 @@ static int __devinit s3cmci_probe(struct platform_device *pdev)
host->complete_what = COMPLETION_NONE; host->complete_what = COMPLETION_NONE;
host->pio_active = XFER_NONE; host->pio_active = XFER_NONE;
host->dma = S3CMCI_DMA;
#ifdef CONFIG_MMC_S3C_PIODMA #ifdef CONFIG_MMC_S3C_PIODMA
host->dodma = host->pdata->dma; host->dodma = host->pdata->dma;
#endif #endif
...@@ -1665,10 +1680,21 @@ static int __devinit s3cmci_probe(struct platform_device *pdev) ...@@ -1665,10 +1680,21 @@ static int __devinit s3cmci_probe(struct platform_device *pdev)
gpio_direction_input(host->pdata->gpio_wprotect); gpio_direction_input(host->pdata->gpio_wprotect);
} }
if (s3c2410_dma_request(S3CMCI_DMA, &s3cmci_dma_client, NULL) < 0) { /* depending on the dma state, get a dma channel to use. */
dev_err(&pdev->dev, "unable to get DMA channel.\n");
if (s3cmci_host_usedma(host)) {
host->dma = s3c2410_dma_request(DMACH_SDI, &s3cmci_dma_client,
host);
if (host->dma < 0) {
dev_err(&pdev->dev, "cannot get DMA channel.\n");
if (!s3cmci_host_canpio()) {
ret = -EBUSY; ret = -EBUSY;
goto probe_free_gpio_wp; goto probe_free_gpio_wp;
} else {
dev_warn(&pdev->dev, "falling back to PIO.\n");
host->dodma = 0;
}
}
} }
host->clk = clk_get(&pdev->dev, "sdi"); host->clk = clk_get(&pdev->dev, "sdi");
...@@ -1676,7 +1702,7 @@ static int __devinit s3cmci_probe(struct platform_device *pdev) ...@@ -1676,7 +1702,7 @@ static int __devinit s3cmci_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "failed to find clock source.\n"); dev_err(&pdev->dev, "failed to find clock source.\n");
ret = PTR_ERR(host->clk); ret = PTR_ERR(host->clk);
host->clk = NULL; host->clk = NULL;
goto probe_free_host; goto probe_free_dma;
} }
ret = clk_enable(host->clk); ret = clk_enable(host->clk);
...@@ -1738,6 +1764,10 @@ static int __devinit s3cmci_probe(struct platform_device *pdev) ...@@ -1738,6 +1764,10 @@ static int __devinit s3cmci_probe(struct platform_device *pdev)
clk_free: clk_free:
clk_put(host->clk); clk_put(host->clk);
probe_free_dma:
if (s3cmci_host_usedma(host))
s3c2410_dma_free(host->dma, &s3cmci_dma_client);
probe_free_gpio_wp: probe_free_gpio_wp:
if (host->pdata->gpio_wprotect) if (host->pdata->gpio_wprotect)
gpio_free(host->pdata->gpio_wprotect); gpio_free(host->pdata->gpio_wprotect);
...@@ -1796,7 +1826,9 @@ static int __devexit s3cmci_remove(struct platform_device *pdev) ...@@ -1796,7 +1826,9 @@ static int __devexit s3cmci_remove(struct platform_device *pdev)
clk_put(host->clk); clk_put(host->clk);
tasklet_disable(&host->pio_tasklet); tasklet_disable(&host->pio_tasklet);
s3c2410_dma_free(S3CMCI_DMA, &s3cmci_dma_client);
if (s3cmci_host_usedma(host))
s3c2410_dma_free(host->dma, &s3cmci_dma_client);
free_irq(host->irq, host); free_irq(host->irq, host);
......
...@@ -8,9 +8,6 @@ ...@@ -8,9 +8,6 @@
* published by the Free Software Foundation. * published by the Free Software Foundation.
*/ */
/* FIXME: DMA Resource management ?! */
#define S3CMCI_DMA 0
enum s3cmci_waitfor { enum s3cmci_waitfor {
COMPLETION_NONE, COMPLETION_NONE,
COMPLETION_FINALIZE, COMPLETION_FINALIZE,
......
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