Commit 3cf86452 authored Mar 31, 2017 by Ondrej Zary Committed by Tejun Heo Apr 11, 2017

sata_via: Enable hotplug only on VT6421



Commit 57e5568f ("sata_via: Implement hotplug for VT6421") adds
hotplug IRQ handler for VT6421 but enables hotplug on all chips. This
is a bug because it causes "irq xx: nobody cared" error on VT6420 when
hot-(un)plugging a drive:

[  381.839948] irq 20: nobody cared (try booting with the "irqpoll" option)
[  381.840014] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.10.0-rc5+ #148
[  381.840066] Hardware name:          P4VM800/P4VM800, BIOS P1.60 05/29/2006
[  381.840117] Call Trace:
[  381.840167]  <IRQ>
[  381.840225]  ? dump_stack+0x44/0x58
[  381.840278]  ? __report_bad_irq+0x14/0x97
[  381.840327]  ? handle_edge_irq+0xa5/0xa5
[  381.840376]  ? note_interrupt+0x155/0x1cf
[  381.840426]  ? handle_edge_irq+0xa5/0xa5
[  381.840474]  ? handle_irq_event_percpu+0x32/0x38
[  381.840524]  ? handle_irq_event+0x1f/0x38
[  381.840573]  ? handle_fasteoi_irq+0x69/0xb8
[  381.840625]  ? handle_irq+0x4f/0x5d
[  381.840672]  </IRQ>
[  381.840726]  ? do_IRQ+0x2e/0x8b
[  381.840782]  ? common_interrupt+0x2c/0x34
[  381.840836]  ? mwait_idle+0x60/0x82
[  381.840892]  ? arch_cpu_idle+0x6/0x7
[  381.840949]  ? do_idle+0x96/0x18e
[  381.841002]  ? cpu_startup_entry+0x16/0x1a
[  381.841057]  ? start_kernel+0x319/0x31c
[  381.841111]  ? startup_32_smp+0x166/0x168
[  381.841165] handlers:
[  381.841219] [<c12a7263>] ata_bmdma_interrupt
[  381.841274] Disabling IRQ #20

Seems that VT6420 can do hotplug too (there's no documentation) but the
comments say that SCR register access (required for detecting hotplug
events) can cause problems on these chips.

For now, just keep hotplug disabled on anything other than VT6421.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

parent a431ecd2

drivers/ata/sata_via.c

+10 −8

Original line number	Diff line number	Diff line
		@@ -644,6 +644,7 @@ static void svia_configure(struct pci_dev *pdev, int board_id,
		pci_write_config_byte(pdev, SATA_NATIVE_MODE, tmp8);
		}

		if (board_id == vt6421) {
		/* enable IRQ on hotplug */
		pci_read_config_byte(pdev, SVIA_MISC_3, &tmp8);
		if ((tmp8 & SATA_HOTPLUG) != SATA_HOTPLUG) {
		@@ -653,6 +654,7 @@ static void svia_configure(struct pci_dev *pdev, int board_id,
		tmp8 \|= SATA_HOTPLUG;
		pci_write_config_byte(pdev, SVIA_MISC_3, tmp8);
		}
		}

		/*
		* vt6420/1 has problems talking to some drives. The following

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