Rather than to poll in a busy-loop, let's convert into using
read_poll_timeout() and insert a small delay between each polling attempts.
In particular, this avoids hogging the CPU.
Additionally, to convert to read_poll_timeout() we also need to switch from
using a specific number of polling attempts, into a specific timeout in us
instead. The previous 100000 attempts, is translated into a total timeout
of total 1s, as that seemed like reasonable value to pick.
Cc: Sascha Sommer <saschasommer@freenet.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20200508095210.14123-1-ulf.hansson@linaro.org
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/ioport.h>
+#include <linux/iopoll.h>
#include <linux/scatterlist.h>
#include <pcmcia/cistpl.h>
#include <linux/scatterlist.h>
#include <pcmcia/cistpl.h>
/* timeouts */
#define CMD_TIMEOUT 100000
/* timeouts */
#define CMD_TIMEOUT 100000
-#define TRANSFER_TIMEOUT 100000
+#define SDRICOH_DATA_TIMEOUT_US 1000000
/* list of supported pcmcia devices */
static const struct pcmcia_device_id pcmcia_ids[] = {
/* list of supported pcmcia devices */
static const struct pcmcia_device_id pcmcia_ids[] = {
+static bool sdricoh_status_ok(struct sdricoh_host *host, unsigned int status,
+ unsigned int wanted)
+{
+ sdricoh_writel(host, R2E4_STATUS_RESP, status);
+ return status & wanted;
+}
+
static int sdricoh_query_status(struct sdricoh_host *host, unsigned int wanted)
{
static int sdricoh_query_status(struct sdricoh_host *host, unsigned int wanted)
{
- unsigned int timeout = TRANSFER_TIMEOUT;
struct device *dev = host->dev;
struct device *dev = host->dev;
- for (loop = 0; loop < timeout; loop++) {
- status = sdricoh_readl(host, R21C_STATUS);
- sdricoh_writel(host, R2E4_STATUS_RESP, status);
- if (status & wanted)
- break;
- }
-
- if (loop == timeout) {
+ ret = read_poll_timeout(sdricoh_readl, status,
+ sdricoh_status_ok(host, status, wanted),
+ 32, SDRICOH_DATA_TIMEOUT_US, false,
+ host, R21C_STATUS);
+ if (ret) {
dev_err(dev, "query_status: timeout waiting for %x\n", wanted);
return -ETIMEDOUT;
}
dev_err(dev, "query_status: timeout waiting for %x\n", wanted);
return -ETIMEDOUT;
}