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authorRuss Weight <russell.h.weight@intel.com>2021-03-23 15:46:50 -0700
committerMoritz Fischer <mdf@kernel.org>2021-03-24 11:15:04 -0700
commit9a8d3cda8daf54b1f8e67ccb360876379b7e7895 (patch)
tree6b3edaecfaf44801b5bba4e4428b1776ba2bd542 /drivers/fpga/dfl-afu-main.c
parent6f1e376cfc6864a2f46538db909bbd5253c3c146 (diff)
fpga: dfl: afu: harden port enable logic
Port enable is not complete until ACK = 0. Change __afu_port_enable() to guarantee that the enable process is complete by polling for ACK == 0. Signed-off-by: Russ Weight <russell.h.weight@intel.com> Reviewed-by: Tom Rix <trix@redhat.com> Reviewed-by: Matthew Gerlach <matthew.gerlach@linux.intel.com> Acked-by: Wu Hao <hao.wu@intel.com> Signed-off-by: Moritz Fischer <mdf@kernel.org>
Diffstat (limited to 'drivers/fpga/dfl-afu-main.c')
-rw-r--r--drivers/fpga/dfl-afu-main.c35
1 files changed, 24 insertions, 11 deletions
diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c
index 753cda4b2568..7f621e96d3b8 100644
--- a/drivers/fpga/dfl-afu-main.c
+++ b/drivers/fpga/dfl-afu-main.c
@@ -21,6 +21,9 @@
#include "dfl-afu.h"
+#define RST_POLL_INVL 10 /* us */
+#define RST_POLL_TIMEOUT 1000 /* us */
+
/**
* __afu_port_enable - enable a port by clear reset
* @pdev: port platform device.
@@ -32,7 +35,7 @@
*
* The caller needs to hold lock for protection.
*/
-void __afu_port_enable(struct platform_device *pdev)
+int __afu_port_enable(struct platform_device *pdev)
{
struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
void __iomem *base;
@@ -41,7 +44,7 @@ void __afu_port_enable(struct platform_device *pdev)
WARN_ON(!pdata->disable_count);
if (--pdata->disable_count != 0)
- return;
+ return 0;
base = dfl_get_feature_ioaddr_by_id(&pdev->dev, PORT_FEATURE_ID_HEADER);
@@ -49,10 +52,20 @@ void __afu_port_enable(struct platform_device *pdev)
v = readq(base + PORT_HDR_CTRL);
v &= ~PORT_CTRL_SFTRST;
writeq(v, base + PORT_HDR_CTRL);
-}
-#define RST_POLL_INVL 10 /* us */
-#define RST_POLL_TIMEOUT 1000 /* us */
+ /*
+ * HW clears the ack bit to indicate that the port is fully out
+ * of reset.
+ */
+ if (readq_poll_timeout(base + PORT_HDR_CTRL, v,
+ !(v & PORT_CTRL_SFTRST_ACK),
+ RST_POLL_INVL, RST_POLL_TIMEOUT)) {
+ dev_err(&pdev->dev, "timeout, failure to enable device\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
/**
* __afu_port_disable - disable a port by hold reset
@@ -86,7 +99,7 @@ int __afu_port_disable(struct platform_device *pdev)
if (readq_poll_timeout(base + PORT_HDR_CTRL, v,
v & PORT_CTRL_SFTRST_ACK,
RST_POLL_INVL, RST_POLL_TIMEOUT)) {
- dev_err(&pdev->dev, "timeout, fail to reset device\n");
+ dev_err(&pdev->dev, "timeout, failure to disable device\n");
return -ETIMEDOUT;
}
@@ -110,10 +123,10 @@ static int __port_reset(struct platform_device *pdev)
int ret;
ret = __afu_port_disable(pdev);
- if (!ret)
- __afu_port_enable(pdev);
+ if (ret)
+ return ret;
- return ret;
+ return __afu_port_enable(pdev);
}
static int port_reset(struct platform_device *pdev)
@@ -872,11 +885,11 @@ static int afu_dev_destroy(struct platform_device *pdev)
static int port_enable_set(struct platform_device *pdev, bool enable)
{
struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
- int ret = 0;
+ int ret;
mutex_lock(&pdata->lock);
if (enable)
- __afu_port_enable(pdev);
+ ret = __afu_port_enable(pdev);
else
ret = __afu_port_disable(pdev);
mutex_unlock(&pdata->lock);