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Revert "usb: early: convert to readl_poll_timeout_atomic()"

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This reverts commit 796eed4b2342c9d6b26c958e92af91253a2390e1.

This change causes boot lockups when using "arlyprintk=xdbc" because
ktime can not be used at this point in time in the boot process.  Also,
it is not needed for very small delays like this.

Reported-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Cc: Jann Horn <jannh@google.com>
Cc: Chunfeng Yun <chunfeng.yun@mediatek.com>
Fixes: 796eed4b2342 ("usb: early: convert to readl_poll_timeout_atomic()")
Link: https://lore.kernel.org/r/c2b5c9bb-1b75-bf56-3754-b5b18812d65e@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Greg Kroah-Hartman 2021-12-17 16:24:30 +01:00
parent a0b24a5662
commit c4d936efa4
1 changed files with 11 additions and 4 deletions
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15
drivers/usb/early/xhci-dbc.c
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@ -14,7 +14,6 @@
#include <linux/pci_ids.h> #include <linux/pci_ids.h>
#include <linux/memblock.h> #include <linux/memblock.h>
#include <linux/io.h> #include <linux/io.h>
#include <linux/iopoll.h>
#include <asm/pci-direct.h> #include <asm/pci-direct.h>
#include <asm/fixmap.h> #include <asm/fixmap.h>
#include <linux/bcd.h> #include <linux/bcd.h>
@ -136,9 +135,17 @@ static int handshake(void __iomem *ptr, u32 mask, u32 done, int wait, int delay)
{ {
u32 result; u32 result;
return readl_poll_timeout_atomic(ptr, result, /* Can not use readl_poll_timeout_atomic() for early boot things */
((result & mask) == done), do {
delay, wait); result = readl(ptr);
result &= mask;
if (result == done)
return 0;
udelay(delay);
wait -= delay;
} while (wait > 0);
return -ETIMEDOUT;
} }
static void __init xdbc_bios_handoff(void) static void __init xdbc_bios_handoff(void)