[PATCH 03/30] rapidio/tsi721: fix hardcoded MRRS setting

From: Alexandre Bounine
Date: Fri Feb 05 2016 - 18:35:45 EST


Remove use of hardcoded setting for Maximum Read Request Size (MRRS) value
and use one set by PCIe bus driver.
Using hardcoded value can cause PCIe bus errors on platforms that have
tsi721 device on PCIe path that allows only smaller read request sizes.

This fix is applicable to kernel versions starting from v3.2.

Signed-off-by: Alexandre Bounine <alexandre.bounine@xxxxxxx>
Cc: Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>
Cc: Aurelien Jacquiot <a-jacquiot@xxxxxx>
Cc: Andre van Herk <andre.van.herk@xxxxxxxxxxxxxxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/rapidio/devices/tsi721.c | 6 ++----
1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
index eeca70d..f57ee9d 100644
--- a/drivers/rapidio/devices/tsi721.c
+++ b/drivers/rapidio/devices/tsi721.c
@@ -2426,11 +2426,9 @@ static int tsi721_probe(struct pci_dev *pdev,

BUG_ON(!pci_is_pcie(pdev));

- /* Clear "no snoop" and "relaxed ordering" bits, use default MRRS. */
+ /* Clear "no snoop" and "relaxed ordering" bits. */
pcie_capability_clear_and_set_word(pdev, PCI_EXP_DEVCTL,
- PCI_EXP_DEVCTL_READRQ | PCI_EXP_DEVCTL_RELAX_EN |
- PCI_EXP_DEVCTL_NOSNOOP_EN,
- PCI_EXP_DEVCTL_READRQ_512B);
+ PCI_EXP_DEVCTL_RELAX_EN | PCI_EXP_DEVCTL_NOSNOOP_EN, 0);

/* Adjust PCIe completion timeout. */
pcie_capability_clear_and_set_word(pdev, PCI_EXP_DEVCTL2, 0xf, 0x2);
--
1.7.8.4