On 10/10/22 08:06, 'Jason A. Donenfeld' via BCM-KERNEL-FEEDBACK-LIST,PDL
wrote:
Rather than busy looping, yield back to the scheduler and sleep for a
bit in the event that there's no data. This should hopefully prevent the
stalls that Mark reported:
<6>[ 3.362859] Freeing initrd memory: 16196K
<3>[ 23.160131] rcu: INFO: rcu_sched self-detected stall on CPU
<3>[ 23.166057] rcu: 0-....: (2099 ticks this GP) idle=03b4/1/0x40000002 softirq=28/28 fqs=1050
<4>[ 23.174895] (t=2101 jiffies g=-1147 q=2353 ncpus=4)
<4>[ 23.180203] CPU: 0 PID: 49 Comm: hwrng Not tainted 6.0.0 #1
<4>[ 23.186125] Hardware name: BCM2835
<4>[ 23.189837] PC is at bcm2835_rng_read+0x30/0x6c
<4>[ 23.194709] LR is at hwrng_fillfn+0x71/0xf4
<4>[ 23.199218] pc : [<c07ccdc8>] lr : [<c07cb841>] psr: 40000033
<4>[ 23.205840] sp : f093df70 ip : 00000000 fp : 00000000
<4>[ 23.211404] r10: c3c7e800 r9 : 00000000 r8 : c17e6b20
<4>[ 23.216968] r7 : c17e6b64 r6 : c18b0a74 r5 : c07ccd99 r4 : c3f171c0
<4>[ 23.223855] r3 : 000fffff r2 : 00000040 r1 : c3c7e800 r0 : c3f171c0
<4>[ 23.230743] Flags: nZcv IRQs on FIQs on Mode SVC_32 ISA Thumb Segment none
<4>[ 23.238426] Control: 50c5387d Table: 0020406a DAC: 00000051
<4>[ 23.244519] CPU: 0 PID: 49 Comm: hwrng Not tainted 6.0.0 #1
Link: https://lore.kernel.org/all/Y0QJLauamRnCDUef@xxxxxxxxxxxxx/
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Acked-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
--
Florian
