[PATCH v2] mfd:rtsx: do retry when dma transfer error

steven_feng
2017-01-04T09:49:39Z

From: steven_feng <steven_feng@realsil.com.cn>

the request should be reissued when dma transfer error.
for rts5227, the clock freq need to step reduce when error occurred.

Signed-off-by: steven_feng <steven_feng@realsil.com.cn>
---
drivers/mfd/rtsx_pcr.c | 16 ++++++++++++++--
include/linux/mfd/rtsx_pci.h | 4 ++++
2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/mfd/rtsx_pcr.c b/drivers/mfd/rtsx_pcr.c
index 98029ee..63ee0ac 100644
--- a/drivers/mfd/rtsx_pcr.c
+++ b/drivers/mfd/rtsx_pcr.c
@@ -30,6 +30,7 @@
#include <linux/platform_device.h>
#include <linux/mfd/core.h>
#include <linux/mfd/rtsx_pci.h>
+#include <linux/mmc/card.h>
#include <asm/unaligned.h>

#include "rtsx_pcr.h"
@@ -452,8 +453,12 @@ int rtsx_pci_dma_transfer(struct rtsx_pcr *pcr, struct scatterlist *sglist,
}

spin_lock_irqsave(&pcr->lock, flags);
- if (pcr->trans_result == TRANS_RESULT_FAIL)
- err = -EINVAL;
+ if (pcr->trans_result == TRANS_RESULT_FAIL) {
+ err = -EILSEQ;
+ if (pcr->dma_error_count < 8)
+ pcr->dma_error_count++;
+ }
+
else if (pcr->trans_result == TRANS_NO_DEVICE)
err = -ENODEV;
spin_unlock_irqrestore(&pcr->lock, flags);
@@ -659,6 +664,12 @@ int rtsx_pci_switch_clock(struct rtsx_pcr *pcr, unsigned int card_clock,
if (err < 0)
return err;

+ /* each time dma transfer error occurs, card clock decreased by 20MHz */
+ if (card_clock == UHS_SDR104_MAX_DTR &&
+ pcr->dma_error_count && PCI_PID(pcr) == RTS5227_DEVICE_ID)
+ card_clock = UHS_SDR104_MAX_DTR -
+ pcr->dma_error_count * 20000000;
+
card_clock /= 1000000;
pcr_dbg(pcr, "Switch card clock to %dMHz\n", card_clock);

@@ -894,6 +905,7 @@ static irqreturn_t rtsx_pci_isr(int irq, void *dev_id)
pcr->card_removed |= SD_EXIST;
pcr->card_inserted &= ~SD_EXIST;
}
+ pcr->dma_error_count = 0;
}

if (int_reg & MS_INT) {
diff --git a/include/linux/mfd/rtsx_pci.h b/include/linux/mfd/rtsx_pci.h
index 7eb7cba..751c4042 100644
--- a/include/linux/mfd/rtsx_pci.h
+++ b/include/linux/mfd/rtsx_pci.h
@@ -850,6 +850,8 @@

#define rtsx_pci_init_cmd(pcr) ((pcr)->ci = 0)

+#define RTS5227_DEVICE_ID 0x5227
+
struct rtsx_pcr;

struct pcr_handle {
@@ -957,6 +959,8 @@ struct rtsx_pcr {

int num_slots;
struct rtsx_slot *slots;
+
+ u8 dma_error_count;
};

#define CHK_PCI_PID(pcr, pid) ((pcr)->pci->device == (pid))
--
1.9.1