Hi Paul,
On 03.06.2017 01:40, Paul Burton wrote:
Resets of the EG20T MAC on the MIPS Boston development board take longer
than the 1000 loops that pch_gbe_wait_clr_bit was performing. Rather
than simply increasing the number of loops, switch to using
readl_poll_timeout_atomic() from linux/iopoll.h in order to provide some
independence from the speed of the CPU.
#define DRV_VERSION "1.01"
@@ -318,13 +319,11 @@ s32 pch_gbe_mac_read_mac_addr(struct pch_gbe_hw *hw)
*/
static void pch_gbe_wait_clr_bit(void *reg, u32 bit)
{
+ int err;
u32 tmp;
- /* wait busy */
- tmp = 1000;
- while ((ioread32(reg) & bit) && --tmp)
- cpu_relax();
- if (!tmp)
+ err = readl_poll_timeout_atomic(reg, tmp, !(tmp & bit), 10, 500);
+ if (err)
pr_err("Error: busy bit is not cleared\n");
}
This new timeout value appears to be too low - I'm seeing plenty of
timeout warnings now and ultimately the device fails to initialise:
[ 7.541876] pch_gbe: EG20T PCH Gigabit Ethernet Driver - version 1.01
[ 7.566451] pch_gbe: Error: busy bit is not cleared
[ 7.572654] pch_gbe: Error: busy bit is not cleared
[ 7.578727] pch_gbe: Error: busy bit is not cleared
[ 7.587814] pch_gbe 0000:02:00.1: Invalid MAC address, interface
disabled.
[ 7.595605] pch_gbe 0000:02:00.1: MAC address : 00:00:00:00:00:00
[ 7.606451] pch_gbe: Error: busy bit is not cleared
[ 7.612572] pch_gbe: Error: busy bit is not cleared
[ 7.618618] pch_gbe: Error: busy bit is not cleared
<...>
[ 10.063351] pch_gbe 0000:02:00.1 eth0: Error: Invalid MAC address
[ 10.074713] pch_gbe: Error: busy bit is not cleared
[ 10.081030] pch_gbe: Error: busy bit is not cleared
[ 10.087178] pch_gbe: Error: busy bit is not cleared
[ 10.093328] pch_gbe: Error: busy bit is not cleared
[ 10.100883] pch_gbe 0000:02:00.1 eth0: Error End
[ 10.106272] IP-Config: Failed to open eth0
My tests show that a timeout value as big as 20000 may be required to
make it work reliably ...
Marcin
