[nrf fromlist] modules: nrf_wifi: Fix bustest QSPI crash

Commit 5e25283821a("drivers: wifi: Create dedicated mem pool for Wi-Fi
driver") introduced OSAL dependecy in the Zephyr QSPI driver for HL
read, but in bustest we don't enable nrf_wifi OS module, so, it crashes
here. And we should not be using OSAL APIs in Zephyr code anyway.

And in this case we don't even need to use the heap, so, move the rx
buffer to stack.

Upstream PR #: 93303

Signed-off-by: Chaitanya Tata <[email protected]>

Author: krish2718

include/zephyr/drivers/wifi/nrf_wifi/bus/rpu_hw_if.h

@@ -31,6 +31,11 @@ enum {
 	NUM_MEM_BLOCKS
 };
 
+/* Keeping it higher to avoid changing it ofter, but modify this value
+ * if rpu_7002_memmap is changed.
+ */
+#define NRF_WIFI_QSPI_SLAVE_MAX_LATENCY 4
+
 extern char blk_name[][15];
 extern uint32_t rpu_7002_memmap[][3];
 

modules/nrf_wifi/bus/qspi_if.c

@@ -23,8 +23,8 @@
 #include <hal/nrf_clock.h>
 #include <hal/nrf_gpio.h>
 
+#include <zephyr/drivers/wifi/nrf_wifi/bus/rpu_hw_if.h>
 #include "spi_nor.h"
-#include "osal_api.h"
 
 /* The QSPI bus node which the NRF70 is on */
 #define QSPI_IF_BUS_NODE DT_NODELABEL(qspi)
@@ -1290,15 +1290,14 @@ int qspi_read(unsigned int addr, void *data, int len)
 int qspi_hl_readw(unsigned int addr, void *data)
 {
 	int status;
-	uint8_t *rxb = NULL;
 	uint32_t len = 4;
+	uint8_t rxb[4 + (NRF_WIFI_QSPI_SLAVE_MAX_LATENCY * 4)];
 
-	len = len + (4 * qspi_cfg->qspi_slave_latency);
+	len += (4 * qspi_cfg->qspi_slave_latency);
 
-	rxb = nrf_wifi_osal_mem_alloc(len);
-
-	if (rxb == NULL) {
-		LOG_ERR("%s: ERROR ENOMEM line %d", __func__, __LINE__);
+	if (len > sizeof(rxb)) {
+		LOG_ERR("%s: len exceeded, check NRF_WIFI_QSPI_SLAVE_MAX_LATENCY (len=%u, rxb=%zu)",
+			__func__, (unsigned int)len, sizeof(rxb));
 		return -ENOMEM;
 	}
 
@@ -1314,8 +1313,6 @@ int qspi_hl_readw(unsigned int addr, void *data)
 
 	*(uint32_t *)data = *(uint32_t *)(rxb + (len - 4));
 
-	nrf_wifi_osal_mem_free(rxb);
-
 	return status;
 }