[PATCH 1/2] wifi: ath11k: Flush the posted write after writing to PCIE_SOC_GLOBAL_RESET

[PATCH 1/2] wifi: ath11k: Flush the posted write after writing to PCIE_SOC_GLOBAL_RESET

[Manivannan Sadhasivam]

ath11k_pci_soc_global_reset() tries to reset the device by writing to the
PCIE_SOC_GLOBAL_RESET register. But it doesn't do a read-back to ensure
that the write gets flushed to the device before the delay.

This may lead to the delay on the host to be insufficient, if the posted
write doesn't reach the device before the delay.

So add a read-back after writing to the PCIE_SOC_GLOBAL_RESET register and
before the delay.

Compile tested only.

Fixes: f3c603d412b3 ("ath11k: reset MHI during power down and power up")
Reported-by: Alex Williamson <alex@shazbot.org>
Closes: https://lore.kernel.org/linux-pci/20260622160822.09350246@shazbot.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
---
 drivers/net/wireless/ath/ath11k/pci.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/ath/ath11k/pci.c b/drivers/net/wireless/ath/ath11k/pci.c
index 35bb9e7a63a2..a163168f3617 100644
--- a/drivers/net/wireless/ath/ath11k/pci.c
+++ b/drivers/net/wireless/ath/ath11k/pci.c
@@ -199,6 +199,8 @@ static void ath11k_pci_soc_global_reset(struct ath11k_base *ab)
 	val |= PCIE_SOC_GLOBAL_RESET_V;
 
 	ath11k_pcic_write32(ab, PCIE_SOC_GLOBAL_RESET, val);
+	/* Flush the posted write to the device */
+	ath11k_pcic_read32(ab, PCIE_SOC_GLOBAL_RESET);
 
 	/* TODO: exact time to sleep is uncertain */
 	delay = 10;
@@ -208,6 +210,8 @@ static void ath11k_pci_soc_global_reset(struct ath11k_base *ab)
 	val &= ~PCIE_SOC_GLOBAL_RESET_V;
 
 	ath11k_pcic_write32(ab, PCIE_SOC_GLOBAL_RESET, val);
+	/* Flush the posted write to the device */
+	ath11k_pcic_read32(ab, PCIE_SOC_GLOBAL_RESET);
 
 	mdelay(delay);
 
-- 
2.43.0

[PATCH 2/2] wifi: ath12k: Flush the posted write after writing to PCIE_SOC_GLOBAL_RESET

[Manivannan Sadhasivam]

ath12k_pci_soc_global_reset() tries to reset the device by writing to the
PCIE_SOC_GLOBAL_RESET register. But it doesn't do a read-back to ensure
that the write gets flushed to the device before the delay.

This may lead to the delay on the host to be insufficient, if the posted
write doesn't reach the device before the delay.

So add a read-back after writing to the PCIE_SOC_GLOBAL_RESET register and
before the delay.

Compile tested only.

Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
Reported-by: Alex Williamson <alex@shazbot.org>
Closes: https://lore.kernel.org/linux-pci/20260622160822.09350246@shazbot.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
---
 drivers/net/wireless/ath/ath12k/pci.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/ath/ath12k/pci.c b/drivers/net/wireless/ath/ath12k/pci.c
index d9a22d6afbb0..fee4129ea405 100644
--- a/drivers/net/wireless/ath/ath12k/pci.c
+++ b/drivers/net/wireless/ath/ath12k/pci.c
@@ -188,6 +188,8 @@ static void ath12k_pci_soc_global_reset(struct ath12k_base *ab)
 	val |= PCIE_SOC_GLOBAL_RESET_V;
 
 	ath12k_pci_write32(ab, PCIE_SOC_GLOBAL_RESET, val);
+	/* Flush the posted write to the device */
+	ath12k_pci_read32(ab, PCIE_SOC_GLOBAL_RESET);
 
 	/* TODO: exact time to sleep is uncertain */
 	delay = 10;
@@ -197,6 +199,8 @@ static void ath12k_pci_soc_global_reset(struct ath12k_base *ab)
 	val &= ~PCIE_SOC_GLOBAL_RESET_V;
 
 	ath12k_pci_write32(ab, PCIE_SOC_GLOBAL_RESET, val);
+	/* Flush the posted write to the device */
+	ath12k_pci_read32(ab, PCIE_SOC_GLOBAL_RESET);
 
 	mdelay(delay);
 
-- 
2.43.0

Re: [PATCH 2/2] wifi: ath12k: Flush the posted write after writing to PCIE_SOC_GLOBAL_RESET

[Raj Kumar Bhagat]

On 23-06-2026 19:46, Manivannan Sadhasivam wrote:
> ath12k_pci_soc_global_reset() tries to reset the device by writing to the
> PCIE_SOC_GLOBAL_RESET register. But it doesn't do a read-back to ensure
> that the write gets flushed to the device before the delay.
> 
> This may lead to the delay on the host to be insufficient, if the posted
> write doesn't reach the device before the delay.
> 
> So add a read-back after writing to the PCIE_SOC_GLOBAL_RESET register and
> before the delay.
> 
> Compile tested only.
> 
> Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
> Reported-by: Alex Williamson<alex@shazbot.org>
> Closes:https://lore.kernel.org/linux-pci/20260622160822.09350246@shazbot.org
> Signed-off-by: Manivannan Sadhasivam<manivannan.sadhasivam@oss.qualcomm.com>
> ---
>   drivers/net/wireless/ath/ath12k/pci.c | 4 ++++
>   1 file changed, 4 insertions(+)

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.6-01243-QCAHKSWPL_SILICONZ-1

Tested-by: Raj Kumar Bhagat <raj.bhagat@oss.qualcomm.com>

Validated with 25+ successful ath12k and ath12k_wifi7 module reload
(rmmod/insmod) cycles on QCN9274.

-- 
Raj Bhagat

Re: [PATCH 2/2] wifi: ath12k: Flush the posted write after writing to PCIE_SOC_GLOBAL_RESET

[Raj Kumar Bhagat]

On 23-06-2026 19:46, Manivannan Sadhasivam wrote:
> ath12k_pci_soc_global_reset() tries to reset the device by writing to the
> PCIE_SOC_GLOBAL_RESET register. But it doesn't do a read-back to ensure
> that the write gets flushed to the device before the delay.
> 
> This may lead to the delay on the host to be insufficient, if the posted
> write doesn't reach the device before the delay.
> 
> So add a read-back after writing to the PCIE_SOC_GLOBAL_RESET register and
> before the delay.
> 
> Compile tested only.
> 
> Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
> Reported-by: Alex Williamson<alex@shazbot.org>
> Closes:https://lore.kernel.org/linux-pci/20260622160822.09350246@shazbot.org
> Signed-off-by: Manivannan Sadhasivam<manivannan.sadhasivam@oss.qualcomm.com>
> ---
>   drivers/net/wireless/ath/ath12k/pci.c | 4 ++++
>   1 file changed, 4 insertions(+)

Reviewed-by: Raj Kumar Bhagat <raj.bhagat@oss.qualcomm.com>

Re: [PATCH 2/2] wifi: ath12k: Flush the posted write after writing to PCIE_SOC_GLOBAL_RESET

[Baochen Qiang]

On 6/23/2026 10:16 PM, Manivannan Sadhasivam wrote:
> ath12k_pci_soc_global_reset() tries to reset the device by writing to the
> PCIE_SOC_GLOBAL_RESET register. But it doesn't do a read-back to ensure
> that the write gets flushed to the device before the delay.
> 
> This may lead to the delay on the host to be insufficient, if the posted
> write doesn't reach the device before the delay.
> 
> So add a read-back after writing to the PCIE_SOC_GLOBAL_RESET register and
> before the delay.
> 
> Compile tested only.
> 
> Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
> Reported-by: Alex Williamson <alex@shazbot.org>
> Closes: https://lore.kernel.org/linux-pci/20260622160822.09350246@shazbot.org
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>

Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>

Re: [PATCH 1/2] wifi: ath11k: Flush the posted write after writing to PCIE_SOC_GLOBAL_RESET

[Raj Kumar Bhagat]

On 23-06-2026 19:46, Manivannan Sadhasivam wrote:
> ath11k_pci_soc_global_reset() tries to reset the device by writing to the
> PCIE_SOC_GLOBAL_RESET register. But it doesn't do a read-back to ensure
> that the write gets flushed to the device before the delay.
> 
> This may lead to the delay on the host to be insufficient, if the posted
> write doesn't reach the device before the delay.
> 
> So add a read-back after writing to the PCIE_SOC_GLOBAL_RESET register and
> before the delay.
> 
> Compile tested only.
> 
> Fixes: f3c603d412b3 ("ath11k: reset MHI during power down and power up")
> Reported-by: Alex Williamson<alex@shazbot.org>
> Closes:https://lore.kernel.org/linux-pci/20260622160822.09350246@shazbot.org
> Signed-off-by: Manivannan Sadhasivam<manivannan.sadhasivam@oss.qualcomm.com>
> ---
>   drivers/net/wireless/ath/ath11k/pci.c | 4 ++++
>   1 file changed, 4 insertions(+)

Reviewed-by: Raj Kumar Bhagat <raj.bhagat@oss.qualcomm.com>

Re: [PATCH 1/2] wifi: ath11k: Flush the posted write after writing to PCIE_SOC_GLOBAL_RESET

[Baochen Qiang]

On 6/23/2026 10:16 PM, Manivannan Sadhasivam wrote:
> ath11k_pci_soc_global_reset() tries to reset the device by writing to the
> PCIE_SOC_GLOBAL_RESET register. But it doesn't do a read-back to ensure
> that the write gets flushed to the device before the delay.
> 
> This may lead to the delay on the host to be insufficient, if the posted
> write doesn't reach the device before the delay.
> 
> So add a read-back after writing to the PCIE_SOC_GLOBAL_RESET register and
> before the delay.
> 
> Compile tested only.
> 
> Fixes: f3c603d412b3 ("ath11k: reset MHI during power down and power up")
> Reported-by: Alex Williamson <alex@shazbot.org>
> Closes: https://lore.kernel.org/linux-pci/20260622160822.09350246@shazbot.org
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>

Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>

Re: [PATCH 1/2] wifi: ath11k: Flush the posted write after writing to PCIE_SOC_GLOBAL_RESET

[Jeff Johnson]

On Tue, 23 Jun 2026 16:16:48 +0200, Manivannan Sadhasivam wrote:
> ath11k_pci_soc_global_reset() tries to reset the device by writing to the
> PCIE_SOC_GLOBAL_RESET register. But it doesn't do a read-back to ensure
> that the write gets flushed to the device before the delay.
> 
> This may lead to the delay on the host to be insufficient, if the posted
> write doesn't reach the device before the delay.
> 
> [...]

Applied, thanks!

[1/2] wifi: ath11k: Flush the posted write after writing to PCIE_SOC_GLOBAL_RESET
      commit: 0fe8010fc5b147607fc19ba010ba469afc95f35f
[2/2] wifi: ath12k: Flush the posted write after writing to PCIE_SOC_GLOBAL_RESET
      commit: 55f3aa06951cac78b0206bde961c8cf11929a27a

Best regards,
-- 
Jeff Johnson <jeff.johnson@oss.qualcomm.com>