[U-Boot] [PATCH v2] pci: Avoid assigning PCI resources that are below 0x1000
commit b7598a43f2b4 ("[PATCH] Avoid assigning PCI resources from zero address") only moved the bus lower address to 0x1000 if the given bus start address is zero. The comment said 0x1000 is a reasonable starting value, hence we'd better apply the same adjustment when the given bus start address is below 0x1000.
Signed-off-by: Bin Meng bmeng.cn@gmail.com
---
Changes in v2: - avoid changing res->bus_start
drivers/pci/pci_auto_common.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pci_auto_common.c b/drivers/pci/pci_auto_common.c index 1837873..84908e6 100644 --- a/drivers/pci/pci_auto_common.c +++ b/drivers/pci/pci_auto_common.c @@ -21,9 +21,10 @@ void pciauto_region_init(struct pci_region *res) /* * Avoid allocating PCI resources from address 0 -- this is illegal * according to PCI 2.1 and moreover, this is known to cause Linux IDE - * drivers to fail. Use a reasonable starting value of 0x1000 instead. + * drivers to fail. Use a reasonable starting value of 0x1000 instead + * if the bus start address is below 0x1000. */ - res->bus_lower = res->bus_start ? res->bus_start : 0x1000; + res->bus_lower = res->bus_start < 0x1000 ? 0x1000 : res->bus_start; }
void pciauto_region_align(struct pci_region *res, pci_size_t size)
On 05.06.19 16:26, Bin Meng wrote:
commit b7598a43f2b4 ("[PATCH] Avoid assigning PCI resources from zero address") only moved the bus lower address to 0x1000 if the given bus start address is zero. The comment said 0x1000 is a reasonable starting value, hence we'd better apply the same adjustment when the given bus start address is below 0x1000.
Signed-off-by: Bin Meng bmeng.cn@gmail.com
Reviewed-by: Stefan Roese sr@denx.de
Though again my question, where you did spot an issue with the current implementation?
Thanks, Stefan
Hi Stefan,
On Wed, Jun 5, 2019 at 10:26 PM Bin Meng bmeng.cn@gmail.com wrote:
commit b7598a43f2b4 ("[PATCH] Avoid assigning PCI resources from zero address") only moved the bus lower address to 0x1000 if the given bus start address is zero. The comment said 0x1000 is a reasonable starting value, hence we'd better apply the same adjustment when the given bus start address is below 0x1000.
Signed-off-by: Bin Meng bmeng.cn@gmail.com
Changes in v2:
- avoid changing res->bus_start
Somehow I did not receive your RB in my inbox. However when I look at the patch in patchwork [1], I found you already gave your RB tag, so there must have be something wrong with gmail.
Regarding your question, first it was just pure code review before and at that time I did not spot any actual issue. However I indeed created a test case to trigger the issue.
If I modified qemu-x86_i440fx.dts pci range to have the PCI IO region address starts from 0x100, when Linux boots, it reports the following: [ 0.445751] pci 0000:00:03.0: can't claim BAR 1 [io 0x0140-0x017f]: address conflict with 0000:00:01.1 [io 0x0170-0x0177]
With my patch, there is no longer such complaints from the kernel driver.
[1] http://patchwork.ozlabs.org/patch/1110510/
Regards, Bin
On Wed, Jun 05, 2019 at 07:26:44AM -0700, Bin Meng wrote:
commit b7598a43f2b4 ("[PATCH] Avoid assigning PCI resources from zero address") only moved the bus lower address to 0x1000 if the given bus start address is zero. The comment said 0x1000 is a reasonable starting value, hence we'd better apply the same adjustment when the given bus start address is below 0x1000.
Signed-off-by: Bin Meng bmeng.cn@gmail.com Reviewed-by: Stefan Roese sr@denx.de
Applied to u-boot/master, thanks!
participants (3)
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Bin Meng -
Stefan Roese -
Tom Rini