From 23f8e4bf7cf0e2125b6d798cc85c031951c763d3 Mon Sep 17 00:00:00 2001 From: Bartlomiej Zolnierkiewicz Date: Thu, 1 May 2008 14:08:51 +0200 Subject: [PATCH] ide: fix early setup of hwif->host_flags On Thursday 01 May 2008, Jeremy Kerr wrote: > Hi all, > > On QS20 Cell machines, Linus' current git tree explodes on boot: > > SiI680: IDE controller (0x1095:0x0680 rev 0x02) at PCI slot > 0000:00:0a.0 > SiI680: BASE CLOCK == 133 > SiI680: 100% native mode on irq 51 > ide0: MMIO-DMA > ide1: MMIO-DMA > Unable to handle kernel paging request for data at address > 0xa000100081220080 > Faulting instruction address: 0xc000000000024748 > cpu 0x2: Vector: 300 (Data Access) at [c00000001e143420] > pc: c000000000024748: ._insw_ns+0x10/0x30 > lr: c000000000037fc4: .spiderpci_readsw+0x24/0x6c > sp: c00000001e1436a0 > msr: 9000000000001032 > dar: a000100081220080 > dsisr: 40000000 > current = 0xc00000003d060000 > paca = 0xc000000000623880 > pid = 1, comm = swapper > enter ? for help > [link register ] c000000000037fc4 .spiderpci_readsw+0x24/0x6c > [c00000001e1436a0] c00000000062ce63 (unreliable) > [c00000001e143730] c0000000000379d4 .iowa_readsw+0x78/0xa8 > [c00000001e1437c0] c000000000037a98 .iowa_insw+0x94/0xd4 > [c00000001e143850] c00000000022a190 .ata_input_data+0x298/0x2ec > [c00000001e143910] c00000000022b600 .try_to_identify+0x2c0/0x6d4 > [c00000001e1439d0] c00000000022bb54 .do_probe+0x140/0x35c > [c00000001e143a80] c00000000022bfbc .ide_probe_port+0x24c/0x670 > [c00000001e143b50] c00000000022d09c .ide_device_add_all+0x2ec/0x690 > [c00000001e143c00] c00000000022d4a4 .ide_device_add+0x64/0x74 > [c00000001e143c90] c00000000022f834 .ide_setup_pci_device+0x58/0x7c > [c00000001e143d30] c00000000038bdf8 > [c00000001e143e10] c000000000486fb0 .ide_scan_pcibus+0x8c/0x178 > [c00000001e143ea0] c000000000460c00 .kernel_init+0x1c4/0x344 > [c00000001e143f90] c000000000024a1c .kernel_thread+0x4c/0x68 > > It looks like we're trying to do PIO accesses (which appear to be > broken, but that's another issue) to this MMIO device. In > ata_input_data, we see that: > > u8 mmio = (hwif->host_flags & IDE_HFLAG_MMIO) ? 1 : 0; > > Gives mmio == 0. > > (what's the difference between hwif->mmio and ID_HFLAG_MMIO?) > > In the siimage driver, hwif->host flags is initially set up correctly > (host_flags includes IDE_HFLAG_MMIO), but we then *clear* this bit in > ide_init_port: > > hwif->host_flags = d->host_flags; > > where d is the struct ide_port_info for this chipset. In my case, > d->host_flags is 0x0. It looks like this will be the same for all of > the siimage chipsets. Don't over-write hwif->host_flags in ide_init_port(), some host drivers set IDE_HFLAG_MMIO or IDE_HFLAG_NO_IO_32BIT host flag early. Thanks to Jeremy Kerr for the excellent analysis of the bug. Reported-by: Jeremy Kerr Tested-by: Jeremy Kerr Cc: Sergei Shtylyov Cc: Ben Herrenschmidt Signed-off-by: Bartlomiej Zolnierkiewicz --- drivers/ide/ide-probe.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c index 099a0fe1745b..591deda3f86a 100644 --- a/drivers/ide/ide-probe.c +++ b/drivers/ide/ide-probe.c @@ -1347,7 +1347,8 @@ static void ide_init_port(ide_hwif_t *hwif, unsigned int port, (d->host_flags & IDE_HFLAG_FORCE_LEGACY_IRQS)) hwif->irq = port ? 15 : 14; - hwif->host_flags = d->host_flags; + /* ->host_flags may be set by ->init_iops (or even earlier...) */ + hwif->host_flags |= d->host_flags; hwif->pio_mask = d->pio_mask; /* ->set_pio_mode for DTC2278 is currently limited to port 0 */ -- 2.20.1