Re: [PATCH 2/3] iommu/fsl: Fix the device domain attach condition.

From: Joerg Roedel
Date: Fri Jul 04 2014 - 06:54:38 EST


Hmm,

On Tue, Jun 24, 2014 at 07:27:16PM +0530, Varun Sethi wrote:
> - old_domain_info = find_domain(dev);
> + old_domain_info = dev->archdata.iommu_domain;
> if (old_domain_info && old_domain_info->domain != dma_domain) {
> spin_unlock_irqrestore(&device_domain_lock, flags);
> detach_device(dev, old_domain_info->domain);

Wouldn't this set dev->archdata.iommu_domain to NULL anyway, so that ...

> @@ -399,7 +394,7 @@ static void attach_device(struct fsl_dma_domain *dma_domain, int liodn, struct d
> * the info for the first LIODN as all
> * LIODNs share the same domain
> */
> - if (!old_domain_info)
> + if (!dev->archdata.iommu_domain)
> dev->archdata.iommu_domain = info;

We already know that it _must_ be NULL here?

> spin_unlock_irqrestore(&device_domain_lock, flags);

This would shrink down the patch to:

diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
index 93072ba..d21b554 100644
--- a/drivers/iommu/fsl_pamu_domain.c
+++ b/drivers/iommu/fsl_pamu_domain.c
@@ -399,8 +399,7 @@ static void attach_device(struct fsl_dma_domain *dma_domain, int liodn, struct d
* the info for the first LIODN as all
* LIODNs share the same domain
*/
- if (!old_domain_info)
- dev->archdata.iommu_domain = info;
+ dev->archdata.iommu_domain = info;
spin_unlock_irqrestore(&device_domain_lock, flags);

}


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