From: Amisha Patel<[email protected]>
In some situations like, chip wake-up with powersave enabled, SPI
commands are failing temporarily. Reissuing commands after reset helps
to overcome the failure. So, add the retry limit and reset command
sequence API for read/write SPI commands.
Signed-off-by: Amisha Patel <[email protected]>
---
v2->v3: Changed goto logic to for loop based on review.
v1->v2: Removed some false indentations and unnecessary if condition
check of result variable
---
drivers/net/wireless/microchip/wilc1000/spi.c | 148 ++++++++++++------
1 file changed, 103 insertions(+), 45 deletions(-)
diff --git a/drivers/net/wireless/microchip/wilc1000/spi.c b/drivers/net/wireless/microchip/wilc1000/spi.c
index b0fc5e68feec..77b4cdff73c3 100644
--- a/drivers/net/wireless/microchip/wilc1000/spi.c
+++ b/drivers/net/wireless/microchip/wilc1000/spi.c
@@ -74,6 +74,7 @@ static int wilc_spi_reset(struct wilc *wilc);
#define CMD_SINGLE_READ 0xca
#define CMD_RESET 0xcf
+#define SPI_RETRY_MAX_LIMIT 10
#define SPI_ENABLE_VMM_RETRY_LIMIT 2
/* SPI response fields (section 11.1.2 in ATWILC1000 User Guide): */
@@ -830,59 +831,91 @@ static int wilc_spi_special_cmd(struct wilc *wilc, u8 cmd)
return 0;
}
+static void wilc_spi_reset_cmd_sequence(struct wilc *wl, u8 attempt, u32 addr)
+{
+ struct spi_device *spi = to_spi_device(wl->dev);
+ struct wilc_spi *spi_priv = wl->bus_data;
+
+ if (!spi_priv->probing_crc)
+ dev_err(&spi->dev, "Reset and retry %d %x\n", attempt, addr);
+
+ usleep_range(1000, 1100);
+ wilc_spi_reset(wl);
+ usleep_range(1000, 1100);
+}
+
static int wilc_spi_read_reg(struct wilc *wilc, u32 addr, u32 *data)
{
struct spi_device *spi = to_spi_device(wilc->dev);
int result;
u8 cmd = CMD_SINGLE_READ;
u8 clockless = 0;
+ u8 i;
- if (addr < WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
+ if (addr <= WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
/* Clockless register */
cmd = CMD_INTERNAL_READ;
clockless = 1;
}
- result = wilc_spi_single_read(wilc, cmd, addr, data, clockless);
- if (result) {
+ for (i = 0; i < SPI_RETRY_MAX_LIMIT; i++) {
+ result = wilc_spi_single_read(wilc, cmd, addr, data, clockless);
+ if (!result) {
+ le32_to_cpus(data);
+ return 0;
+ }
+
+ /* retry is not applicable for clockless registers */
+ if (clockless)
+ break;
+
dev_err(&spi->dev, "Failed cmd, read reg (%08x)...\n", addr);
- return result;
+ wilc_spi_reset_cmd_sequence(wilc, i, addr);
}
- le32_to_cpus(data);
-
- return 0;
+ return result;
}
static int wilc_spi_read(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
{
struct spi_device *spi = to_spi_device(wilc->dev);
int result;
+ u8 i;
if (size <= 4)
return -EINVAL;
- result = wilc_spi_dma_rw(wilc, CMD_DMA_EXT_READ, addr, buf, size);
- if (result) {
+ for (i = 0; i < SPI_RETRY_MAX_LIMIT; i++) {
+ result = wilc_spi_dma_rw(wilc, CMD_DMA_EXT_READ, addr,
+ buf, size);
+ if (!result)
+ return 0;
+
dev_err(&spi->dev, "Failed cmd, read block (%08x)...\n", addr);
- return result;
+
+ wilc_spi_reset_cmd_sequence(wilc, i, addr);
}
- return 0;
+ return result;
}
static int spi_internal_write(struct wilc *wilc, u32 adr, u32 dat)
{
struct spi_device *spi = to_spi_device(wilc->dev);
int result;
+ u8 i;
- result = wilc_spi_write_cmd(wilc, CMD_INTERNAL_WRITE, adr, dat, 0);
- if (result) {
+ for (i = 0; i < SPI_RETRY_MAX_LIMIT; i++) {
+ result = wilc_spi_write_cmd(wilc, CMD_INTERNAL_WRITE, adr,
+ dat, 0);
+ if (!result)
+ return 0;
dev_err(&spi->dev, "Failed internal write cmd...\n");
- return result;
+
+ wilc_spi_reset_cmd_sequence(wilc, i, adr);
}
- return 0;
+ return result;
}
static int spi_internal_read(struct wilc *wilc, u32 adr, u32 *data)
@@ -890,17 +923,22 @@ static int spi_internal_read(struct wilc *wilc, u32 adr, u32 *data)
struct spi_device *spi = to_spi_device(wilc->dev);
struct wilc_spi *spi_priv = wilc->bus_data;
int result;
+ u8 i;
- result = wilc_spi_single_read(wilc, CMD_INTERNAL_READ, adr, data, 0);
- if (result) {
+ for (i = 0; i < SPI_RETRY_MAX_LIMIT; i++) {
+ result = wilc_spi_single_read(wilc, CMD_INTERNAL_READ, adr,
+ data, 0);
+ if (!result) {
+ le32_to_cpus(data);
+ return 0;
+ }
if (!spi_priv->probing_crc)
dev_err(&spi->dev, "Failed internal read cmd...\n");
- return result;
- }
- le32_to_cpus(data);
+ wilc_spi_reset_cmd_sequence(wilc, i, adr);
+ }
- return 0;
+ return result;
}
/********************************************
@@ -915,20 +953,27 @@ static int wilc_spi_write_reg(struct wilc *wilc, u32 addr, u32 data)
int result;
u8 cmd = CMD_SINGLE_WRITE;
u8 clockless = 0;
+ u8 i;
- if (addr < WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
+ if (addr <= WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
/* Clockless register */
cmd = CMD_INTERNAL_WRITE;
clockless = 1;
}
- result = wilc_spi_write_cmd(wilc, cmd, addr, data, clockless);
- if (result) {
+ for (i = 0; i < SPI_RETRY_MAX_LIMIT; i++) {
+ result = wilc_spi_write_cmd(wilc, cmd, addr, data, clockless);
+ if (!result)
+ return 0;
+
dev_err(&spi->dev, "Failed cmd, write reg (%08x)...\n", addr);
- return result;
- }
- return 0;
+ if (clockless)
+ break;
+
+ wilc_spi_reset_cmd_sequence(wilc, i, addr);
+ }
+ return result;
}
static int spi_data_rsp(struct wilc *wilc, u8 cmd)
@@ -981,6 +1026,7 @@ static int wilc_spi_write(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
{
struct spi_device *spi = to_spi_device(wilc->dev);
int result;
+ u8 i;
/*
* has to be greated than 4
@@ -988,26 +1034,38 @@ static int wilc_spi_write(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
if (size <= 4)
return -EINVAL;
- result = wilc_spi_dma_rw(wilc, CMD_DMA_EXT_WRITE, addr, NULL, size);
- if (result) {
- dev_err(&spi->dev,
- "Failed cmd, write block (%08x)...\n", addr);
- return result;
- }
+ for (i = 0; i < SPI_RETRY_MAX_LIMIT; i++) {
+ result = wilc_spi_dma_rw(wilc, CMD_DMA_EXT_WRITE, addr,
+ NULL, size);
+ if (result) {
+ dev_err(&spi->dev,
+ "Failed cmd, write block (%08x)...\n", addr);
+ wilc_spi_reset_cmd_sequence(wilc, i, addr);
+ continue;
+ }
- /*
- * Data
- */
- result = spi_data_write(wilc, buf, size);
- if (result) {
- dev_err(&spi->dev, "Failed block data write...\n");
- return result;
- }
+ /*
+ * Data
+ */
+ result = spi_data_write(wilc, buf, size);
+ if (result) {
+ dev_err(&spi->dev, "Failed block data write...\n");
+ wilc_spi_reset_cmd_sequence(wilc, i, addr);
+ continue;
+ }
- /*
- * Data response
- */
- return spi_data_rsp(wilc, CMD_DMA_EXT_WRITE);
+ /*
+ * Data response
+ */
+ result = spi_data_rsp(wilc, CMD_DMA_EXT_WRITE);
+ if (result) {
+ dev_err(&spi->dev, "Failed block data rsp...\n");
+ wilc_spi_reset_cmd_sequence(wilc, i, addr);
+ continue;
+ }
+ break;
+ }
+ return result;
}
/********************************************
--
2.25.1
<[email protected]> wrote:
> From: Amisha Patel<[email protected]>
>
> In some situations like, chip wake-up with powersave enabled, SPI
> commands are failing temporarily. Reissuing commands after reset helps
> to overcome the failure. So, add the retry limit and reset command
> sequence API for read/write SPI commands.
>
> Signed-off-by: Amisha Patel <[email protected]>
Patch applied to wireless-next.git, thanks.
6fd879f9783b wifi: wilc1000: add SPI commands retry mechanism
--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches