2020-07-20 17:37:43

by Anand Moon

Subject: [PATCH v5] phy: samsung: Use readl_poll_timeout function

Instead of a busy waiting while loop using udelay
use readl_poll_timeout function to check the condition
is met or timeout occurs in crport_handshake function.
readl_poll_timeout is called in non atomic context so
it safe to sleep until the condition is met.

Signed-off-by: Anand Moon <[email protected]>
---
Changes v5:
--Fix the indentation, checkpatch warning.
--Drop the Fix tags.
Changes v4:
Rebased on to of patch [0] https://patchwork.kernel.org/patch/11651673/
--Fix the commit message.
--Fix the error timeout condition for -ETIMEDOUT
Changes v3:
--Fix the commit message.
--Drop the variable, used the value directly.
Changes v2:
--used the default timeout values.
--Added missing Fixed tags.
---
drivers/phy/samsung/phy-exynos5-usbdrd.c | 39 ++++++++----------------
1 file changed, 12 insertions(+), 27 deletions(-)

diff --git a/drivers/phy/samsung/phy-exynos5-usbdrd.c b/drivers/phy/samsung/phy-exynos5-usbdrd.c
index 7f6279fb4f8f..c45ed9cabc5e 100644
--- a/drivers/phy/samsung/phy-exynos5-usbdrd.c
+++ b/drivers/phy/samsung/phy-exynos5-usbdrd.c
@@ -16,6 +16,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
+#include <linux/iopoll.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
@@ -556,41 +557,25 @@ static int exynos5_usbdrd_phy_power_off(struct phy *phy)
static int crport_handshake(struct exynos5_usbdrd_phy *phy_drd,
u32 val, u32 cmd)
{
- u32 usec = 100;
unsigned int result;
+ int err;

writel(val | cmd, phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);

- do {
- result = readl(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1);
- if (result & PHYREG1_CR_ACK)
- break;
-
- udelay(1);
- } while (usec-- > 0);
-
- if (!usec) {
- dev_err(phy_drd->dev,
- "CRPORT handshake timeout1 (0x%08x)\n", val);
- return -ETIME;
+ err = readl_poll_timeout(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1,
+ result, (result & PHYREG1_CR_ACK), 1, 100);
+ if (err == -ETIMEDOUT) {
+ dev_err(phy_drd->dev, "CRPORT handshake timeout1 (0x%08x)\n", val);
+ return err;
}

- usec = 100;
-
writel(val, phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);

- do {
- result = readl(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1);
- if (!(result & PHYREG1_CR_ACK))
- break;
-
- udelay(1);
- } while (usec-- > 0);
-
- if (!usec) {
- dev_err(phy_drd->dev,
- "CRPORT handshake timeout2 (0x%08x)\n", val);
- return -ETIME;
+ err = readl_poll_timeout(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1,
+ result, !(result & PHYREG1_CR_ACK), 1, 100);
+ if (err == -ETIMEDOUT) {
+ dev_err(phy_drd->dev, "CRPORT handshake timeout2 (0x%08x)\n", val);
+ return err;
}

return 0;
--
2.27.0

2020-08-23 14:08:26

by Vinod Koul

Subject: Re: [PATCH v5] phy: samsung: Use readl_poll_timeout function

On 20-07-20, 17:35, Anand Moon wrote:
> Instead of a busy waiting while loop using udelay
> use readl_poll_timeout function to check the condition
> is met or timeout occurs in crport_handshake function.
> readl_poll_timeout is called in non atomic context so
> it safe to sleep until the condition is met.

Applied, thanks

--
~Vinod