Thread (12 messages) 12 messages, 3 authors, 2018-07-19

Re: [PATCH v2 2/4] pci: dwc: pci-dra7xx: Enable errata i870 for both EP and RC mode

From: Lorenzo Pieralisi <hidden>
Date: 2018-07-19 11:16:03
Also in: linux-omap, linux-pci, lkml

On Thu, Jul 19, 2018 at 04:04:34PM +0530, Vignesh R wrote:
Hi Lorenzo,

On Wednesday 18 July 2018 04:32 PM, Lorenzo Pieralisi wrote:
quoted
On Wed, Jun 27, 2018 at 05:59:17PM +0530, Vignesh R wrote:
quoted
Errata i870 is applicable in both EP and RC mode. Therefore rename
function dra7xx_pcie_ep_unaligned_memaccess(), that implements errata
workaround, to dra7xx_pcie_unaligned_memaccess() and call it from a
common place. So, that errata workaround is applied for both modes of
operation.

Reported-by: Chris Welch <redacted>
Signed-off-by: Vignesh R <vigneshr@ti.com>
---
 drivers/pci/controller/dwc/pci-dra7xx.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-dra7xx.c b/drivers/pci/controller/dwc/pci-dra7xx.c
index 345aab56ce8b..95d9076e3fde 100644
--- a/drivers/pci/controller/dwc/pci-dra7xx.c
+++ b/drivers/pci/controller/dwc/pci-dra7xx.c
@@ -542,7 +542,7 @@ static const struct of_device_id of_dra7xx_pcie_match[] = {
 };
 
 /*
- * dra7xx_pcie_ep_unaligned_memaccess: workaround for AM572x/AM571x Errata i870
+ * dra7xx_pcie_unaligned_memaccess: workaround for AM572x/AM571x Errata i870
  * @dra7xx: the dra7xx device where the workaround should be applied
  *
  * Access to the PCIe slave port that are not 32-bit aligned will result
@@ -552,7 +552,7 @@ static const struct of_device_id of_dra7xx_pcie_match[] = {
  *
  * To avoid this issue set PCIE_SS1_AXI2OCP_LEGACY_MODE_ENABLE to 1.
  */
-static int dra7xx_pcie_ep_unaligned_memaccess(struct device *dev)
+static int dra7xx_pcie_unaligned_memaccess(struct device *dev)
 {
 	int ret;
 	struct device_node *np = dev->of_node;
@@ -695,6 +695,10 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev)
 	if (dra7xx->link_gen < 0 || dra7xx->link_gen > 2)
 		dra7xx->link_gen = 2;
 
+	ret = dra7xx_pcie_unaligned_memaccess(dev);
+	if (ret)
+		dev_err(dev, "WA for Errata i870 not appplied. Update DT\n");
Hi Vignesh,

Nit: s/appplied/applied
Oops, let me know if you want me to resend with this fixed.
I can fix it, no problem but see below.
quoted
Two questions:

- Current code applies the unaligned_memaccess() workaround for all
  compatible variants. This is fine for current controllers (since
  they are all affected), the code path above will have to be
  reworked if there is any other compatible IP re-using the driver
  that does not require the workaround.
There are no compatible IPs that don't require this workaround. Also, I
don't see this IP being re-used in future. If you insist, I can add a
errata flag
I do not insist, I just pointed this out ;-)
quoted
- How do you want this series to go upstream ? If it goes via arm-soc,
  which I think it should, here is my ACK on this patch:
Patch 1 and 2(dt bindings update and driver patch) can go in via PCI
tree. And DT changes(patch 3 and 4) can be picked up by Tony via
omap/arm-soc tree. They are mostly independent and should not cause any
problems. Does that sound good?
It should be fine but technically as soon as patch (2) is applied we
would have a regression if patches (3) and (4) are applied separately.

You could re-order the series and send everything via arm-soc.

It is not such a big deal, your choice, please let me know.

Thanks,
Lorenzo
quoted
Acked-by: Lorenzo Pieralisi <redacted>
Thanks!
quoted
Please let me know if I can drop this series from the PCI patchwork.

Thanks,
Lorenzo
quoted
+
 	switch (mode) {
 	case DW_PCIE_RC_TYPE:
 		if (!IS_ENABLED(CONFIG_PCI_DRA7XX_HOST)) {
@@ -717,10 +721,6 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev)
 		dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_DEVICE_TYPE,
 				   DEVICE_TYPE_EP);
 
-		ret = dra7xx_pcie_ep_unaligned_memaccess(dev);
-		if (ret)
-			goto err_gpio;
-
 		ret = dra7xx_add_pcie_ep(dra7xx, pdev);
 		if (ret < 0)
 			goto err_gpio;
-- 
2.18.0
-- 
Regards
Vignesh
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