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]>
---
v1 -> v2: Removed some false indentations and unnecessary if condition
check of result variable
---
drivers/net/wireless/microchip/wilc1000/spi.c | 92 ++++++++++++++++---
1 file changed, 81 insertions(+), 11 deletions(-)
diff --git a/drivers/net/wireless/microchip/wilc1000/spi.c b/drivers/net/wireless/microchip/wilc1000/spi.c
index b0fc5e68feec..bdde444394dc 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): */
@@ -830,23 +831,45 @@ 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 retry_limit = SPI_RETRY_MAX_LIMIT;
- if (addr < WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
+ if (addr <= WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
/* Clockless register */
cmd = CMD_INTERNAL_READ;
clockless = 1;
}
+retry:
result = wilc_spi_single_read(wilc, cmd, addr, data, clockless);
if (result) {
dev_err(&spi->dev, "Failed cmd, read reg (%08x)...\n", addr);
- return result;
+
+ /* retry is not applicable for clockless registers */
+ if (clockless || !retry_limit)
+ return result;
+
+ wilc_spi_reset_cmd_sequence(wilc, retry_limit, addr);
+ retry_limit--;
+ goto retry;
}
le32_to_cpus(data);
@@ -858,14 +881,22 @@ 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 retry_limit = SPI_RETRY_MAX_LIMIT;
if (size <= 4)
return -EINVAL;
+retry:
result = wilc_spi_dma_rw(wilc, CMD_DMA_EXT_READ, addr, buf, size);
if (result) {
dev_err(&spi->dev, "Failed cmd, read block (%08x)...\n", addr);
- return result;
+
+ if (!retry_limit)
+ return result;
+
+ wilc_spi_reset_cmd_sequence(wilc, retry_limit, addr);
+ retry_limit--;
+ goto retry;
}
return 0;
@@ -875,11 +906,19 @@ static int spi_internal_write(struct wilc *wilc, u32 adr, u32 dat)
{
struct spi_device *spi = to_spi_device(wilc->dev);
int result;
+ u8 retry_limit = SPI_RETRY_MAX_LIMIT;
+retry:
result = wilc_spi_write_cmd(wilc, CMD_INTERNAL_WRITE, adr, dat, 0);
if (result) {
dev_err(&spi->dev, "Failed internal write cmd...\n");
- return result;
+
+ if (!retry_limit)
+ return result;
+
+ wilc_spi_reset_cmd_sequence(wilc, retry_limit, adr);
+ retry_limit--;
+ goto retry;
}
return 0;
@@ -890,12 +929,20 @@ 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 retry_limit = SPI_RETRY_MAX_LIMIT;
+retry:
result = wilc_spi_single_read(wilc, CMD_INTERNAL_READ, adr, data, 0);
if (result) {
if (!spi_priv->probing_crc)
dev_err(&spi->dev, "Failed internal read cmd...\n");
- return result;
+
+ if (!retry_limit)
+ return result;
+
+ wilc_spi_reset_cmd_sequence(wilc, retry_limit, adr);
+ retry_limit--;
+ goto retry;
}
le32_to_cpus(data);
@@ -915,19 +962,26 @@ static int wilc_spi_write_reg(struct wilc *wilc, u32 addr, u32 data)
int result;
u8 cmd = CMD_SINGLE_WRITE;
u8 clockless = 0;
+ u8 retry_limit = SPI_RETRY_MAX_LIMIT;
- if (addr < WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
+ if (addr <= WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
/* Clockless register */
cmd = CMD_INTERNAL_WRITE;
clockless = 1;
}
+retry:
result = wilc_spi_write_cmd(wilc, cmd, addr, data, clockless);
if (result) {
dev_err(&spi->dev, "Failed cmd, write reg (%08x)...\n", addr);
- return result;
- }
+ if (clockless || !retry_limit)
+ return result;
+
+ wilc_spi_reset_cmd_sequence(wilc, retry_limit, addr);
+ retry_limit--;
+ goto retry;
+ }
return 0;
}
@@ -981,6 +1035,7 @@ 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 retry_limit = SPI_RETRY_MAX_LIMIT;
/*
* has to be greated than 4
@@ -988,11 +1043,12 @@ static int wilc_spi_write(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
if (size <= 4)
return -EINVAL;
+retry:
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;
+ goto fail;
}
/*
@@ -1001,13 +1057,27 @@ static int wilc_spi_write(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
result = spi_data_write(wilc, buf, size);
if (result) {
dev_err(&spi->dev, "Failed block data write...\n");
- return result;
+ goto fail;
}
/*
* Data response
*/
- return spi_data_rsp(wilc, CMD_DMA_EXT_WRITE);
+ result = spi_data_rsp(wilc, CMD_DMA_EXT_WRITE);
+ if (result) {
+ dev_err(&spi->dev, "Failed block data rsp...\n");
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ if (retry_limit) {
+ wilc_spi_reset_cmd_sequence(wilc, retry_limit, addr);
+ retry_limit--;
+ goto retry;
+ }
+ return result;
}
/********************************************
--
2.25.1
<[email protected]> writes:
> 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]>
[...]
> +retry:
> result = wilc_spi_single_read(wilc, cmd, addr, data, clockless);
> if (result) {
> dev_err(&spi->dev, "Failed cmd, read reg (%08x)...\n", addr);
> - return result;
> +
> + /* retry is not applicable for clockless registers */
> + if (clockless || !retry_limit)
> + return result;
> +
> + wilc_spi_reset_cmd_sequence(wilc, retry_limit, addr);
> + retry_limit--;
> + goto retry;
> }
A for loop is recommended over a goto loop. Also in this case I find
'retry_limit == 0' more readable than '!retry_limit', it's a counter
anyway.
--
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